Page 1 (for Asia, Middle Near and Other Areas) Please file and use this manual together with the Service Manual for model KX-FT21LA, Order No.KM79905276C3 This Service Manual indicates the main differences between: Original KX-FT21LA and KX-FT21BX/KX-FT21BX-W. WARNING This service information is designed for experienced repair technicians only and is not designed for use by the general public.
Page 2 ** The 15 second speed is based upon the CCITT No. 1 Test Chart . Note: Any details given in these instructions are subject to change without notice. The pictures and illustrations in these instructions may vary slightly from the actual product. (Model KX-FT21BX/KX-FT21BX-W)
Page 3 KX-FT21BX/KX-FT21BX-W CONTROL PANEL (Change from original page 13) Power cord Handset cord To the power outlet Telephone (220V– 240 V) line cord To the single Connect to “LINE”. telephone line (Model KX-FT21BX/KX-FT21BX-W)
Page 4 563 CCD position adjustment value set 00~30 mm --------- 570 Break % select 1:61% 2:67% 571 ITS auto redial time set 00~99 572 ITS auto redial line disconnection time set 001~999 set 573 Remote turn-on ring number set 01~99 (Model KX-FT21BX/KX-FT21BX-W)
Page 5 844 Original setting 1:NORMAL/2:LIGHT/3:DARKER NORMAL 991 Transmit basic list 1: START --------- 992 Transmit advanced list 1: START --------- 994 Transmit journal report 1: START --------- 996 Journal 3 1: START --------- 999 Transmit service list 1: START --------- (Model KX-FT21BX/KX-FT21BX-W)
Page 6 KX-FT21BX/KX-FT21BX-W 4-3. USER MODE (The list below is an example of the SYSTEM SETUP LIST the unit prints out.) (Change from original page 82) Code Set Value Set Value Code (Model KX-FT21BX/KX-FT21BX-W)
Page 7 When you check voltage in DUMMY LOAD to check voltage a power supply unit alone, use this dummy load. If the dummy load is not available, connect the main P.C.B. to the analog P.C.B. 4.7k 24.5V±0.5V CN301 5.0V±0.25V : Volt Meter (Model KX-FT21BX/KX-FT21BX-W)
Page 8 Replace Q101 and R105. Power ON 24V output OK? Power OFF (Control circuit check) Are R107, R109 5V output OK? and D106 OK? Replace the broken part and IC101. Power OFF Power ON Replace D202. 24V output OK? Power OFF (Model KX-FT21BX/KX-FT21BX-W)
Page 9 This is due to a very high voltage through the Gate circuit which is composed of R107, R109, D106 and IC101. You should change all of the parts listed as follows. F101, Q101, R107, R109, D106, IC101 (D201) If D201 is broken, the oscillation circuit in the power supply cannot operate. Check it with an electric tester. (Model KX-FT21BX/KX-FT21BX-W)
Page 10 815 Sensor check Pres s "START". 1:NORMAL Use this feature when you need to 844 Original s etting 1, 2, 3 NORMAL 2:LIGHT transmit and copy a document with very 3:DARKER faint writing or very dark writing. (Model KX-FT21BX/KX-FT21BX-W) -10-...
Page 11 The input current is rectified by D101,D102,D103 and D104 and charges C106 to make DC voltage. Then it supplies power to the converter circuit. [Kick-on voltage circuit] Bias is applied to the Q101 gate via this circuit when the AC power is turned on and Q101 begins operating. (Model KX-FT21BX/KX-FT21BX-W) -11-...
Page 12 Also, when the current load becomes too large, in order to decrease the voltage output, the increase in is controlled and the output voltage is stabilized. Therefore, basically the timing: Ton/Toff of Q1 controls the output voltage. Output/Input voltage value of ratio heavy load light load increases = Duty ratio (Model KX-FT21BX/KX-FT21BX-W) -12-...
Page 13 If the 24V output increases because the error detecting circuit or control circuit is broken, IC101 will recognize this signal and output becomes 0V. Dummy load method (to quickly check the power supply output) Refer to 2.3.3.6. Power Supply Board Section. (Model KX-FT21BX/KX-FT21BX-W) -13-...
Page 14 KX-FT21BX/KX-FT21BX-W MEMO (Model KX-FT21BX/KX-FT21BX-W) -14-...
Page 15 KX-FT21BX/KX-FT21BX-W KX-FT21BX/KX-FT21BX-W SCHEMATIC DIAGRAM (ANALOG CIRCUIT) (Change from original page 158) 540V Cycle=13 s Cycle=13 s T101 TRANS TH101 CN301 D105 D201 D102 D101 C202 D103 D104 1000p/1K D109 R223 C205 Q101 R105 1/50 0.22/2 IC201 C102 R102 R103 R123...
Page 16: Type
KX-FT21BX/KX-FT21BX-W KX-FT21BX/KX-FT21BX-W PRINTED CIRCUIT BOARD (ANALOG BOARD) (Change from original page 159) (COMPONENT VIEW) (BOTTOM VIEW) CAUTION SRF913EK MITSUMI ELEC. CO., LTD. FOR CONTINUED PROTECTION AGAINST RISK OF FIRE. REPLACE ONLY WITH 68-4494A SAME TYPE T3.15AH 250V CN31 T3.15AH 250V 7694V—0...
Page 17 KX-FT21BX/KX-FT21BX-W CABINET,MECHANICAL AND ELECTRICAL PARTS LOCATION (Change from original page 167) 1. OPERATION PANEL SECTION PCB3 (Model KX-FT21BX/KX-FT21BX-W) -17-...
Page 18 KX-FT21BX/KX-FT21BX-W ACCESSORIES AND PACKING MATERIALS (Change from original page 172) A6 , A8 (Model KX-FT21BX/KX-FT21BX-W) -18-...
Page 19 KX-FT21BX/KX-FT21BX-W REPLACEMENT PARTS LIST (Change from original pages 169~175) This replacement parts list is for the KX-FT21BX only. Ref. No. Part No. Part Name & Description Model KX-FT21BX/KX-FT21BX-W PFDG1123Z GEAR, PLATEN Notes: PFHG1064Z SEPARATION RUBBER 1. The marking (RTL) indicates that the Retention Time is limited for this item.
Page 20 KX-FT21BX/KX-FT21BX-W This replacement parts list is for the KX-FT21BX only. Ref. No. Part No. Part Name & Description Ref. No. Part No. Part Name & Description & Value DIGITAL BOARD PARTS (4. GEAR CHASSIS SECTION) PCB1 PFWP1FT21BX DIGITAL BOARD ASS'Y (RTL)
Page 21 KX-FT21BX/KX-FT21BX-W This replacement parts list is for the KX-FT21BX only. Ref. No. Part No. Part Name & Description & Value Ref. No. Part No. Value (CONNECTORS) ERJ3GEYJ473 ERJ3GEYJ433 PQJP8G30Y CONNECTOR, 8PIN ERJ3GEYJ224 220K PQJP16A19Z CONNECTOR, 16PIN ERJ3GEYJ395 3.9M PQJP5G30Y CONNECTOR, 5PIN...
Page 22 KX-FT21BX/KX-FT21BX-W This replacement parts list is for the KX-FT21BX only. Ref. No. Part No. Part Name & Description & Value Pcs Ref. No. Part No. Part Name & Description ECUV1H104ZFV ANALOG BOARD PARTS ECUV1H104ZFV PCB2 PFLP1198BXZA ANALOG BOARD ASS'Y (RTL)
Page 23 (PH O TO ELEC TR IC TR AN SD U CE RS ) PS 1 C NA 1006N PH O TO ELEC TR IC TRA NS DU PS 2 C NA 1006N PH O TO ELEC TR IC TRA NS DU (Model KX-FT21BX/KX-FT21BX-W) -23-...
Page 24 KX-FT21BX/KX-FT21BX-W This replacement parts list is for the KX-FT21BX only. R ef . N o. Part No. Part N am e & Description & Value R ef . N o. Part No. Part N am e & Description & Value...
Page 25 KX-FT21BX/KX-FT21BX-W This replacement parts list is for the KX-FT21BX only. Ref. No. Part No. Part Name & Description & Value Ref. No. Part No. Part Name & Description & Value R130 PQ4R10XJ154 150K PQZZ8K18Z CONNECTOR, 8P R131 PQ4R10XJ154 150K PFZZ13K1Z...
Page 26 KX-FT21BX/KX-FT21BX-W YM (Q) KXFT21BX/KXFT21BX-W Printed in Japan (Model KX-FT21BX/KX-FT21BX-W) -26-...
Page 27 ORDER NO. KM79905276C3 KX-FT21LA PERSONAL FACSIMILE KX-FT21LA (for Latin America) WARNING This service information is designed for experienced repair technicians only and is not designed for use by the general public. It does not contain warnings or cautions to advise non-technical individuals of potential dangers in attempting to service a product. Products powered by electricity should be serviced or repaired only by experienced professional technicians.
Page 28: Table Of Contents
KX-FT21LA When you note the serial number, write down all 11 digits. The serial number may be found on the bottom of the unit. TABLE OF CONTENTS Page INTRODUCTION Safety Precautions ..........................5 Insulation Resistance Test ........................5 For Service Technicians........................5 Battery Caution ..........................
Page 29 KX-FT21LA CIRCUIT OPERATIONS Connection Diagram ........................109 General Block Diagram ......................110~111 Control Section ........................112~120 Facsimile Section ........................120~132 MODEM Section ........................133~140 NCU Section .......................... 141~142 ITS and Monitor Section ......................... 143 EXT. TEL ..........................144~145 Operation Panel ........................146~147 Power Supply Switching Board Section .................
Page 30 KX-FT21LA INTRODUCTION Page Safety Precautions ................... 5 Insulation Resistance Test ................ 5 For Service Technicians ................5 Battery Caution ..................6 AC Caution ....................6 Personal Safety Precautions ..............7 Specifications ................... 8 Optional Accessories ................8 CCITT No.1 Test Chart ................9 Location of Controls .................
Page 31: Safety Precautions
KX-FT21LA SAFETY PRECAUTIONS 1. Before servicing, unplug the AC power cord to prevent an electric shock. 2. When replacing parts, use only the manufacturer’s recommended components. 3. Check the condition of the power cord. Replace if wear or damage is evident. 4.
Page 32: Battery Caution
KX-FT21LA BATTERY CAUTION CAUTION Danger of explosion if battery is incorrectly replaced. Replace only with the same or equivalent type recommended by the manufacture. Dispose of used batteries according to the manufacturer's instructions. AC CAUTION For safety, before closing the lower cabinet, please make sure of the following precautions. 1.The earth lead is fixed with the screw.
Page 33: Personal Safety Precautions
KX-FT21LA PERSONAL SAFETY PRECAUTIONS 1. MOVING SECTIONS OF THE UNIT Be careful not to let your hair, clothes, fingers, accessories, etc., become caught in any moving sections of the unit. The moving sections of the unit are the rollers and a gear. There is a separation roller and a document feed roller which are rotated by the document feed motor.
Page 34 KX-FT21LA FEATURES General Integrated telephone system Desktop type LCD (Liquid Crystal Display) readout Electric Volume Control Help function On-hook dialing Copier function Redialing function Temporary tone dialing Electric telephone directory Facsimile Space Saving Compact Design Resolution: standard/fine/super fine/halftone Copier Function Automatic Document Feeder (10 Sheets) Help Printout Easy-to-view LCD (15 Characters)
Page 35: Specifications
KX-FT21LA SPECIFICATIONS Applicable Lines: Public Switched Telephone Network Document Size: Max. 216 mm (8 ”) in width Max. 600 mm (23 ”) in length Effective Scanning Width: 208mm (8 ”) Recording Paper Size: 216 mm max. 30 m (8 ”• ~98’) roll Effective Printing Width: 208 mm (8 ”)
Page 36: Ccitt No.1 Test Chart
KX-FT21LA CCITT NO. 1 TEST CHART (Actual size) - 10 -...
Page 37: Location Of Controls
KX-FT21LA LOCATION OF CONTROLS 1.OVERVIEW Document entrance Document stacker Document guide(s) Cover open button Document exit - 11 -...
Page 38: Control Panel
KX-FT21LA 2. CONTROL PANEL To print a quick reference To change the receive For the Speed Dial To select a resolution mode For the Telephone Directory with Alpha-Search Display panel The arrow indicator on the For the One-Touch Dial display points to your selected Dial keypad Hookswitch Command keys...
Page 39: Connections
KX-FT21LA CONNECTIONS Power cord Handset cord To the power Telephone outlet (120V) line cord To the single Connect to LINE . telephone line Note: When you operate this products, the power outlet should be near the product and easily accessible. - 13 -...
Page 40: Installation
KX-FT21LA INSTALLATION 3. INSTALLING THE RECORDING PAPER Open the cover by pressing the cover open button and install the recording paper roll. incorrect correct Cover open If the paper is secured with glue or tape, cut button approximately 15 cm (6 inches) from the beginning.
Page 41: Setting Your Logo
KX-FT21LA 4. SETTING YOUR LOGO The logo can be your company, division or name. Press MENU . Display: SYSTEM SET UP (PROG. SISTEMA) Press # , then 0 YOUR LOGO (SU LOGO) Press START/COPY/SET . LOGO= MENU STOP Enter your logo, up to 30 characters, by using (Delete) the dial keypad.
Page 42: Documents You Can Send
KX-FT21LA To select characters with the dial keypad Pressing the dial keys will select a character as shown below. Characters Keys ’ < > " & HYPHEN key (Used to insert a hyphen.) INSERT key (Used to insert one character or one space.) Delete key (Used to delete a character.) STOP key (Used to move the cursor to the left.)
Page 43: Maintenance Items And Component Locations
KX-FT21LA MAINTENANCE ITEMS AND COMPONENT LOCATIONS 1. OUTLINE MAINTENANCE AND REPAIRS ARE PERFORMED USING THE FOLLOWING STEPS. 1) Periodic maintenance Inspect the equipment periodically and if necessary, clean any contaminated parts. 2) Check for breakdowns Look for problems and consider how they arose. If the equipment can be still used, perform copying, self testing or communication testing.
Page 44 KX-FT21LA 2.1 MAINTENANCE LIST CHECK REMARKS OPERATION Remove any foreign matter such as paper. Document Path If the roller is dirty, clean it with a damp cloth then dry thoroughly. See page 19. Rollers If the thermal head is dirty, clean the printing surface with a cloth See pages 20 Thermal Head moistened with denatured alcohol (alcohol without water), then dry...
Page 45 KX-FT21LA 3. MAINTENANCE 3.1 CLEANING THE DOCUMENT FEEDER UNIT If misfeeding occurs frequently or if dirty patterns or black bands appear on a copied or transmitted document, clean the document feeder. Disconnect the power cord and the telephone Telephone line cord. line code Open the cover by pressing the cover open button.
Page 46 KX-FT21LA 3.2 CLEANING THE THERMAL HEAD If dirty patterns or black bands appear on a copied or received document, clean the thermal head. Disconnect the power cord and the telephone line cord. Thermal head Open the cover by pressing the cover open button. Clean the thermal head with a cloth moistened with isopropyl rubbing alcohol, and let it dry thoroughly.
Page 47: Troubleshooting Guide
KX-FT21LA TROUBLESHOOTING GUIDE Page 1. Troubleshooting Summary ..............22 1-1. Troubleshooting ..............22 1-2. Precautions ................22 2. User Recoverable Errors ............... 23 3. Troubleshooting Details ..............25~82 3-1. Outline ................... 25 3-2. Starting troubleshooting ............25 3-3. Table of troubleshooting items ..........26 3-4.
Page 48: Troubleshooting Summary
KX-FT21LA 1. TROUBLESHOOTING SUMMARY 1-1. TROUBLESHOOTING After confirming the problem by asking the user, troubleshoot according to the instructions and observe the following precautions. 1-2. PRECAUTIONS If there is trouble with the print quality or the paper feed, first check if the installation space and the print paper meets the specifications, the paper selection lever/paper thickness lever is set correctly, and the paper is set correctly without any slack.
Page 49: User Recoverable Errors
KX-FT21LA 2. USER RECOVERABLE ERRORS If the unit detects a problem, the following messages will appear on the display. Display Message Cause & Remedy There is something wrong with the unit. Contact our service personnel. CALL SERVICE 1 [This error is displayed when the thermal head dose not warm up. Check the (LLAME SERVICIO 1) thermistor on the thermal head and connector lead.
Page 50: Document Jam
KX-FT21LA Document jam If the unit does not release the document during feeding, remove the jammed document as follows. Open the cover by pressing the cover open button. Remove the jammed document carefully. Close the cover securely by pushing down on both ends.
Page 51: Troubleshooting Details
KX-FT21LA 3. TROUBLESHOOTING DETAILS 3-1. OUTLINE Troubleshooting guide provides a logical path of deduction to assist in locating a fault and suggests methods of restoring the unit to full working condition. Use the reported symptoms of the fault to determine the best troubleshooting method.
Page 52: Table Of Troubleshooting Items
KX-FT21LA 3-3. TABLE OF TROUBLESHOOTING ITEMS FUNCTION SYMPTOM SEE THIS PAGE. Skewed receiving image Printing Expanded print Image is distorted. Black or White vertical lines appear. No feed Paper jam (Auto Document Feeder) Multiple feed Skew Abnormal Abnormal sound from the product mechanical sound Power supply Voltage output is abnormal.
Page 53: Simple Check List
KX-FT21LA 3-4. SIMPLE CHECK LIST FUNCTION REFERENCE JUDGEMENT FAX operation Transmission OK • ^ NG Receiving OK • ^ NG FINE mode Copy operation OK • ^ NG HALF TONE mode OK • ^ NG Handset transceiver / receive OK • ^ NG Monitor sound OK •...
Page 54 KX-FT21LA 3-5. ADF (Auto document feed) SECTION (1) No document feed When using thin paper etc., if the document will not feed. refer to the feed pressure adjustment (page 92). When setting the document, confirm a beep tone. Check the separation Replace the sen- Check the sensor spring for distortion.
Page 55 KX-FT21LA (2) Paper JAM Check the paper jam for cause. Open the lid and check the feed route. Clean or replace the defective parts. Clean each roller. (page 103) Check each sensor’s Confirm if the tip of the read position movement.
Page 56 KX-FT21LA (3) Multiple feed When using thick paper, etc., if the document will not feed. refer to the feed pressure adjustment (page 92). Confirm whether the pad is dirty or not and if it Check the separation pad. is attached correctly. Clean or replace the defective parts.
Page 57 KX-FT21LA (4) Skew Check the document for folds or if tape or staples are attached. Also check Is the document set OK? whether a different size document is set at the same time. Reset the document. Check whether there are foreign Check the feed route.
Page 58 KX-FT21LA (5) Image is distorted (When printing) Please perform the print test (page 88). Go to the thermal head section. (page 82) Check if there are foreign objects Check the feed route. or missing parts. Clean or repair the defective parts. Clean each roller.
Page 59 KX-FT21LA (6) Black or white vertical lines appear. Please perform the print test (page 88). Do lines appear? Replace the thermal head. Clean the white plate and target glass thoroughly. Clean the feed route. Do lines appear? Replace the white plate, CIS unit, etc.
Page 60 KX-FT21LA (7) Skewed receiving image Check the recording Reset the recording paper. paper setling. Replace the recording paper roller. (8) Expanded print (When printing) Check if the cover open Lock the cover open button is locked. button. Clean each roller. (pages 103) - 34 -...
Page 61 KX-FT21LA (9) When copying or printing, an abnormal sound is heard from the unit. Check the document convey- Alternant’s source? ance element. (Next page) Check the printing section. Check the drive gear for damage, inserted foreign Does the recording paper objects and also if the pendulum gear spring is convey ? Confirm the drive attached correctly.
Page 62 KX-FT21LA Check each roller (page 103) for damage, inserted Confirm the document’s foreign objects or improper installation. conveyance drive section. Fix, clean or change the Does it recur? defective part. Grease the motor and gear. Re-grease the spring. (Do not apply large amounts of grease.) (Earth spring A) Does it recur? Change the gear and...
Page 63: Communication Section
KX-FT21LA 3-6 COMMUNICATION SECTION Find the problem in the table shown below, and refer to the corresponding troubleshooting procedure in the reference pages (pages 37-52). Symptom Ref. page Content Possible cause The paper does not feed properly when Troubleshooting Problem with the feeding faxing.
Page 64: Adf Section
KX-FT21LA (1) Defective facsimile section 1 Transmit problem "USER STOPPED" Message on LCD TX Problem Was the STOP key pressed? Operation panel section No problem. (Refer to page 78.) Paper jam? ADF section The document only (Refer to page 28.) partially feeds.
Page 65 KX-FT21LA 2 Sometimes there is a transmit problem. Transmit Error Message on LCD TX Problem Is the document pre-fed? Is auto dial used? Is TX started ? (Does it start feeding?) Was the START key pressed immediately after dialing? The document goes through. Change the "596: Ask the other party to Transmit level set"...
Page 66 KX-FT21LA 3 Receive problem Confirm the following before starting troubleshooting. Is the recording paper installed properly? There is the receiving problem when sometimes the below errors maybe occurred. OUT OF PAPER CHECK COVER Unit OVERHEATED (If it doesn’t return automatically, COVER OPEN, etc., reset the unit.) CHECK DOCUMENT PAPER JAMMED Please refer to "2.
Page 67 KX-FT21LA 4 The unit can copy, but cannot transmit/receive. Connect the unit to the loop simulator. Switch : TX side T-R Connect the oscilloscope. Modem test start (TEST CODE NO. 554) Are four signals output Connect the PBX and at the Tip-Ring? TEL.
Page 68 KX-FT21LA 5 Unit can copy, but cannot transmit/receive long distance or international communications. The following 2 causes can be considered for this. Cause 1: The other party is executing automatic dialling, the call has been received by this unit, and the CED or DIS signal response time is too long.
Page 69 KX-FT21LA (Cause and Countermeasure) (Cause A) When a training signal is transmitted from FAX1 during the communication procedure at the time of transmission from FAX1 to FAX2, there is a delay until the echo canceler operates. S1 is closed so that a part of the head of the training signal may drop out.
Page 70 KX-FT21LA Summary: Long distance and international communication operation COUNTERMEASURE SYMPTOM 1. If possible, manual transmission should be made from the transmission side. 2. If possible, two pauses should be inserted at the end of Does not receive in the automatic mode. the auto dial number on the transmission side.
Page 71 KX-FT21LA (2) Communication error functions How to output the journal Report: 1. Press the MENU button 3 times. 2. Press the START/SET button and then • ¥ button 1 time. 3. Press the START/SET button. 4. All of the error lists will print out. Sample of a journal report DIARIO 25 ENE.
Page 72 KX-FT21LA Counter- SYMPTOM CODE RESULT MODE measure ERROR-NOT YOUR UNIT TRANS DCN is received after transmission of NSC and DTC. (ERROR OTRA UNIDAD) ERROR-NOT YOUR UNIT LECUP DCN is received after DIS transmission. (ERROR OTRA UNIDAD) COMMUNICATION ERROR TRANS 300BPS error (ERROR DE COMUNICACION) COMMUNICATION ERROR LECUP...
Page 73 KX-FT21LA 3 Countermeasure Transmission is stopped when the T1 TIMER expires. Turn ON the FAX monitor func- tion and transmit the data to the same receiver. Is the FAX signal sound (DIS) heard? Is communication OK? Confirm the service parameter and Confirm if the receiver’s FAX machine Confirm if the receiver’s FAX ma-chine compatibility of both the caller’s...
Page 74 KX-FT21LA FTT is received after the transmission of a 2400BPS training signal. Perform the communication test using the LOOP simulator. Is "Fall back" executed from 9600BPS? Modem test (1) Raise the level of transmission. (Do not (TEST CODE NO.554) raise the level above the standard of each country.
Page 75 KX-FT21LA No response after the post message is transmitted three times. Inquire with the receiver if the caller’s document has been sent correctly. Is the data sent correctly? Ask the service section for the receiver’s FAX machine to con- firm the machine condition. RTN and PIN are received.
Page 76 KX-FT21LA No post message Turn ON the FAX monitor func- tion and have the receiver trans- mit the data. Is the FAX signal sound (post message) heard after the image data is received? Ask the service section for the sender’s FAX machine to examine the unit.
Page 77 KX-FT21LA Reception is stopped when the T1 TIMER expires. Perform the communication test us-ing the LOOP simulator and check the machine reception condition. Modem test Is the data sent correctly? (TEST CODE NO.554) Turn ON the FAX monitor func- tion and have the receiver transmit the data again.
Page 78 KX-FT21LA DCN is received after the transmission of NSC and DTC. Confirm if a mechanical problem occurred. E.g., transmission was interrupted or the document was out of place on the receiver side (being polled). Was it a mechanical error as mentioned above? Ask the service section for the Ask the receiver to set the poll receiver’s FAX machine to...
Page 79 KX-FT21LA DCN is received after FTT transmission. No response at the other party after MCF or CFR is transmitted. DCN is received after CFR transmission. Confirm if a mechanical problem occurred. E.g., the caller inter- rupted the transmission. Was it mechanical error as mentioned above? Ask the caller to transmit the data again.
Page 80 KX-FT21LA Polling is not possible. Confirm if a mechanical problem occurred. E.g., transmission was interrupted or the document was out of place on the receiver side (being polled). Was it mechanical error as mentioned above? Ask the receiver to set the Poll Ask the service section for the mode again and perform polling.
Page 81 KX-FT21LA (3) Remote programming If, after the call is connected, the customer describes the situation and it is determined that the problem can be corrected by making parameter changes, this function makes it possible to change parameters such as the user code and service code from another fax (using DTMF tones).
Page 82 KX-FT21LA ‡@ Entering the remote programming mode and changing service codes. If the user is talking with speaker phone, After the call is connected, ask the user to lift the handset. ask the user to press the MENU button. Enter the remote programming ID: "9, 0, 0, 0, ". If nothing is audible, enter "9, 0, 0, 0, "...
Page 83 KX-FT21LA ‡A Program mode table Code Function Set Value Default Remote setting 001 Set the date and time dd/mm/yy hh:mm --------- 002 Your logo --------- --------- 003 Your telephone number --------- --------- 004 Print transmission report 1:ERROR 2:ON 3:OFF ERROR 007 FAX ring count 1 to 4 rings 2 ring...
Page 84 KX-FT21LA Code Function Set Value Default Remote setting 590 FAX auto redial time set 00~99 591 FAX auto redial line disconnection time set 001~999 592 CNG transmit select 1:OFF/2:ALL/3:AUTO 593 Time between CED and 300 bps 1:75/2:500/3:1s 75 ms 594 Overseas DIS detection select 1:1st/2:2nd 595 Receive error limit value set 001~999...
Page 85: Digital Board Section
KX-FT21LA 3-7. Digital board section One of most difficult problems to deal with is when the system will not boot up. The symptom: No response when the power is turned on. (No LCD display, keys are not accepted.) Then first thing to do is check the power source, If there is no problem with the power supply unit, then there is a problem with the digital unit (main board).
Page 86 KX-FT21LA Before we begin mass production, several hundred trial units are produced at the plant, various tests are applied and any malfunctions are analyzed. (In past experiences, digital IC (especially SRAM and ROM) malfunctions are extremely rare after installation in the product.) This may be repaired by replacing the IC, (ASIC etc.).
Page 87 Digital Block Diagram ANALOG PORT CONTROL ROM (IC2) SRAM (IC3) ANALOG FRONT END (IC5) ANALOG SW A0-17 A0-17 (IC6) D0-7 D0-7 TO ANALOG TXOUT 20.736MHz +24V RXIN LED ON H/S RX H/S TX ASIC CIS-CTL CLK, SIG TH ON OPE PANEL HEAD-CTL KSTART,KLATCH,KSCLK,KTXD,KRXD,KIN0,KIN1,KIN2,KIN3 XWDERR...
Page 88 KX-FT21LA The signal lines that must be normal for the system to boot up are listed here [List 1]. For signal lines other than these, even if they malfunction they do not directly affect booting up the system. [List 1] ‡@ D0~D7 (Address/Data Bus) ‡A A0~A16...
Page 89 KX-FT21LA Normal Wave patterns 2 A0~A12 200ns/div, 1V/div D0~D7 200ns/div, 1V/div 3 A15 200ns/div, 1V/div 4 RD 100ns/div, 1V/div 500ns/div, 1V/div 5 ROMCS 6 MDMCS 500ns/div, 1V/div - 63 -...
Page 90 KX-FT21LA For these reasons and the software sequence to boot up the unit, if you use an oscilloscope to judge whether a signal is OK or NG, you must check in the same order as in [List 1]. (If the ASIC (CPU) failed to access the ROM, the ASIC cannot access the SRAM or DRAM normally.) The digital circuit actually operates according to the timing combinations of these signals.
Page 91 KX-FT21LA I/O and Pin No. Diagram RESET XRESET 17 3 RAMCS 6 XRAMCS 106~107 2 A12~A16 110~112 94~105 2 A0~A11 3 WR XWR 115 XRD 113 3 RD XROMCS 112 3 ROMCS 104~111 1 D0~D7 - 65 -...
Page 92 KX-FT21LA SRAM 3 A0~A7 2 A0~A7 1 D0~D7 1 D0~D7 4 A8~A16 2 A8~A14 1~10, 21 11~13 2~12 13~15 23~26 15~19 23~29 17~21 RAMCS ROMCS - 66 -...
Page 93 KX-FT21LA After the power is turned on, the ASIC(CPU) initializes and checks each IC. The ROM, SRAM, and Modem are checked. If initialization fails for the ICs, the system will not boot up. AC POWER ON [1] Power check Problem with the power supply +5 V: Is there +5 V at pin 7 of CN1? unit.
Page 94 KX-FT21LA Put the unit in the test mode and check the voltage at lands A, B, C and D. Tester (TEST LAND) TEST Turn off the power supply. Short using a metallic object, such as tweezers, between the test and GND land, and turn on the AC power. Check the following voltages by using an oscilloscope or tester.
Page 95 KX-FT21LA NG Example Short circuit from the adjacent signal wires. Check for a short circuit in the RA and IC leads and the signal wire at the through hole. Solder waste Solder ball 5V or 3.3V Through hole Short between the signal line and GND. Approx.
Page 96 KX-FT21LA RESET When all waveforms are OK. 3.3V Reconfirm RESET. LCD display Check the LCD. RESET WDERR Example ASIC IC malfunction Chip Open the circuit inside. Replace the CPU. Other NG examples while the power is ON and the LCD displays the following. This display occurs when the temperature of the thermistor on the terminal head is NG.
Page 97 KX-FT21LA MEMO - 71 -...
Page 98: Analog Board Section
KX-FT21LA 3-8. Analog Board Section The analog parts check is actually different than the digital parts check. The signal route is determined by the purpose of the check. For example, the handset TX route begins from the handset microphone and is output in the telephone line. In this route, it is mainly an analog signal.
Page 99 KX-FT21LA (1) Defective ITS (Integrated telephone system) section 1 No handset and monitor transmission/reception Following the ITS section or NCU section, search for the route between the microphone and the telephone line (sending) or between the telephone line and the speaker (receiving) where the signal disappears. Check the components at that point.
Page 100: Power Supply Section
KX-FT21LA 3-9. POWER SUPPLY SECTION (1) Key components for troubleshooting The following components have been known to break frequently : F101, D101-D104, C109, Q101, PC101, ZD203, R302. This comes from our experience with experimental tests. For example : power supply, lightning surge voltage test, withstanding voltage test, intentional short circuit test, etc.
Page 101 KX-FT21LA (2) Troubleshooting flow chart Our recommendation for troubleshooting is as follows. This procedure comes from our experience of troubleshooting in our lab. * Before turning on the power supply, you should check F101. ls F101 open? Replace F101. D101-D104 is short. Replace D101-D104.
Page 102 KX-FT21LA (Control circuit check) Is R102, R103, R104 or R105 short or open? Replace the broken part. 24V output OK? Does D201, Q201, D202 or D203 short? Replace the broken part. 24V output OK? Is R211, R222, VR201, R224 or R225 short or open? Replace the broken part.
Page 103 KX-FT21LA Does D204 short? Replace D204. 24V output OK? Replace the whole board. (3) Broken parts repair details (D101, D102, D103, D104) Check for a short-circuit in terminal 4. If D101, D102, D103 and D104 are short-circuited, F101 will melt (open). In this case, replace all of the parts (D101, D102, D103, D104, F101).
Page 104: Operation Board Section
KX-FT21LA 3-10. OPERATION BOARD SECTION (1) No key operation Do the keys remain pressed Repair the keys. even when you do noting? Perform a KEY CHECK (page 90.) Keys occasionally don’t work. Check if CN6 and CN7 Check IC1. (digital board) or CN1 and CN2 (operation board) (operation board) is disconnected.
Page 105: Sensor Section
KX-FT21LA 3-11. SENSOR SECTION (Refer to page 130~132 for the circuit descriptions.) (1) Check the document sensor (PS1) .." REMOVE DOCUMENT " Check the voltage at pin 3 of CN2. Check the soldering Check the soldering at R12. at Q1, Q3, D1, R11. Document set 4~5V When the pin No document 0V...
Page 106: Read Section
KX-FT21LA 3-12. READ SECTION (Refer to page 124 for circuit operation : SCANNING BLOCK) Clean the location in question. Are the glass surface of the contact image sensor (CIS) and the white panel on the back of the operation block clean? Conduct a scanner test in service mode "555".
Page 107 KX-FT21LA Is pin 154 of IC1 on the digital board Check IC1 on the digital board. at 3.3V? Check IC7 on the digital board. Observe the waveform at test point TP12 Check the image sensor. on the digital board with an oscilloscope (while scanning the white panel).
Page 108: Thermal Head Section
KX-FT21LA 3-13. THERMAL HEAD SECTION (Refer to page 122 for circuit operation) During copying, is the base of Q8 on the Check pin 170 of IC1 on the Make the necessary repairs. digital board. digital board at 4 to 5V ? During copying, are pins 1 to 3 of Q13 Is pin 1 of CN1 on the digital Check the...
Page 109: Programming And Lists
KX-FT21LA 4. PROGRAMMING AND LISTS The programming functions are used to program the various features and functions of the machine, and to test the machine. Programming can be done in both the on-hook and off-hook conditions. This facilitates communication between the user and the service while programming the machine. 4-1.
Page 110 KX-FT21LA 4-3. USER MODE (The list below is an example of the SYSTEM SETUP LIST the unit prints out.) CARACTERISTICAS BASICAS Code Set Value CARACTERISTICAS AVANZADAS Set Value Code Note: The above values are the default values. - 84 -...
Page 111 KX-FT21LA 4-4. SERVICE FUNCTION TABLE Code Function Set Value Effective Range Default Remarks Selects the pause time in 100 msec 501 Setting the pause time 001~600 001~600 X 100 msec 05000 msec steps. Setting the flash recall Selects the line break time during 01~99 X 10 msec 01~99 700 msec...
Page 112 KX-FT21LA Code Function Set Value Effective Range Default Remarks Setting the FAX redial Sets the FAX redial interval during FAX 001~999 sec 001~999 045 sec interval communication. Lets you select the CNG output during FAX transmission. 1: OFF ALL: CNG is output at phase A. Designation of CNG 2: ALL 1, 2, 3...
Page 113 KX-FT21LA 4-5. SERVICE MODE SETTING VALUES (Example of a printed out list) SERVICE DATA LIST Set Value Code SPECIAL SERVICE SETTINGS Code Set Value Note: The above values are the default values. 4-6. OTHER [HISTORY] Display Function DATE Date and time which are set by a user for the first time after purchase. TIME is the expiration from the first power on after purchase.
Page 114: Test Functions
KX-FT21LA 5. TEST FUNCTIONS Code Type of Mode Test mode Function Operation after code input. Prints a test pattern and checks the thermal head for PRINT TEST User mode abnormalities (missing dots, etc.), and also checks the START operation of the reception motor. (Refer to page 90.) Rotates the transmission and reception motors to check the MOTOR TEST Service Mode...
Page 115 KX-FT21LA 5.1 DTMF SIGNAL TONE TRANSMIT SELECTION When set to OFF (=2), the 12 keys and transmission When set to ON (=1), the 12 keys and transmission frequencies are as shown. frequencies are as shown. High (Hz) High Frequency (Hz) Low Frequency (Hz) 1209 1336...
Page 116: Journal 3
KX-FT21LA 6. JOURNAL 3 (Refer to page 91.) Descriptions: (1) ENCODE Compression Code : MH/MR (2) MSLT MSLT means Minimum Scan Line Time. Used only at the factory. (3) RESOLUTION Indicates the resolution of the communication. If multiple pages are transmitted or received, it indicates the last page’s resolution. If there is a communication error, “?”...
Page 117 KX-FT21LA 6-1. PRINTOUT EXAMPLE - 91 -...
Page 118 KX-FT21LA ADJUSTMENTS Page 1. Adjusting the Feeder Pressure ............93 - 92 -...
Page 119: Adjusting The Feeder Pressure
KX-FT21LA 1. ADJUSTING THE FEEDER PRESSURE If no feeding or multiple feeding occurs frequently, adjust the feeder pressure. (1) Open the front lid by pressing the front lid open. (2) Shift the position of the lever using an instrument with a pointed end, such as paper clip. Right: When documents do not feed.
Page 120: Disassembly Instructions
KX-FT21LA DISASSEMBLY INSTRUCTIONS Page How to Remove the Handset Cradle Cabinet ......95 How to Remove the Hook button and Speaker ......96 How to Remove the Operation Block .......... 97 How to Remove the Operation Board and LCD ......98 How to Remove the Bottom Frame ..........
Page 121: How To Remove The Handset Cradle Cabinet
KX-FT21LA HOW TO REMOVE THE HANDSET CRADLE CABINET Ref. No. 1 Procedure 1) Push the front lid open button. 2) Push the tabs with a screwdriver. (See Fig.A.) 3) Remove the handset cradle cabinet. VIEW Caution: Be careful not to damage the tabs with a screwdriver.
Page 122: How To Remove The Hook Button And Speaker
KX-FT21LA HOW TO REMOVE THE HOOK BUTTON AND SPEAKER Ref. No. 2 Procedure 1• ¨2 1) Remove the handset cradle cabinet. 2) Remove the hook button. 3) Remove the speaker. HOOK BUTTON SPEAKER - 96 -...
Page 123: How To Remove The Operation Block
KX-FT21LA Ref. No. 3 HOW TO REMOVE THE OPERATION BLOCK 1) Push the front lid open button in the direction of the arrow to open the operation block. 2) Lift up the lead and remove the arm (See Fig. A.) 3) Remove the arm.(See Fig.
Page 124: How To Remove The Operation Board And Lcd
KX-FT21LA Ref. No. 4 HOW TO REMOVE THE OPERATION BOARD AND LCD Procedure 1) Remove the 4 screws (A) and the operation block cover. 3• ¨4 2) Remove the operation board. 3) Remove the document guides. SEPARATION RUBBER OPERATION PANELCOVER OPERATION BOARD DOCUMENT GUIDE DOCUMENT GUIDE...
Page 125: How To Remove The Bottom Frame
KX-FT21LA Ref. No. 5 HOW TO REMOVE THE BOTTOM FRAME Procedure 1) Remove the 8 screws (A). 2) Remove the bottom frame. Ref. No. 6 HOW TO REMOVE THE ANALOG BOARD AND DIGITAL BOARD Procedure 1) Remove the 2 screws (A). 5•...
Page 126: How To Remove The Power Supply Board And Ac Inlet
KX-FT21LA Ref. No. 7 HOW TO REMOVE THE POWER SUPPLY BOARD AND AC INLET Procedure 5• ¨6• ¨7 1) Remove the 1 screw (A) and remove the connector. 2) Remove the power supply board. 1) Remove the 1 screw (B). 3) Remove the AC inlet.
Page 127: How To Remove The Motor Block
KX-FT21LA Ref. No.7 HOW TO REMOVE THE MOTOR BLOCK Procedure 5• ¨ 8 1) Remove the 2 screw (A). 2) Remove the MOTOR BLOCK. MOTOR BLOCK - 101 -...
Page 128: 8(A). How To Remove The Motor Block
KX-FT21LA Ref. No.8(a) HOW TO REMOVE THE MOTOR BLOCK Procedure 8(a) 1) Remove the SW. 2) Remove the MOTOR. 3) Remove the CHASSIS. 1) Remove the SPRING. CHASSIS 2) Remove the gear (1). 3) Remove the gear (2). 4) Remove the gear (3). 5) Remove the screws (A).
Page 129: How To Remove The Image Sensor
KX-FT21LA Ref. No. 9 HOW TO REMOVE THE IMAGE SENSOR Procedure 1) Remove the sheet (Fig. A). 2) Remove the image sensor. SHEET(Refer to Fig.A) IMAGE SENSOR (: CIS) Fig. A Ref. No. 10 HOW TO REMOVE THE ROLLERS (Fig.A) Procedure 1) Remove the image sensor.(See Ref.
Page 130: How To Remove The Thermal Head Roller
KX-FT21LA Ref. No. 11 HOW TO REMOVE THE THERMAL HEAD ROLLER Procedure 1) Push the front lid open button in the direction of the arrow to open the operation block. 2) Remove the head cover. 3) Remove the lock lever shaft with a screwdriver as shown in Fig. A. 4) Remove the 2 connector.
Page 131: How To Remove The Document Tray
KX-FT21LA Ref. No. 12 HOW TO REMOVE THE DOCUMENT TRAY Procedure 1) Push the bottom of the tray in the direction of the arrows. PAPER STACKER [(Ref. No.6) for page ] Harness installation position (To prevent harnesses from getting caught during the installation.) - 105 -...
Page 132: How To Replace The Flat Package Ic
KX-FT21LA HOW TO REPLACE THE FLAT PACKAGE IC If you do not have the special tools (for example: SPOT HEATER) to remove the SPOT HEATER'S Flat IC, if you have solder (large amount), a soldering iron, and a cutter knife, you can easily remove the ICs even if there are more than 100 pins. 1.
Page 133 KX-FT21LA After removing the Flat IC and when attaching a new IC, remove any of the excess solder on the land using the soldering wire, etc. If the excess solder is not removed from the land, the IC will slip and not be attached properly. 3.
Page 134: Circuit Operations
KX-FT21LA CIRCUIT OPERATIONS Page 1. Connection Diagram ............... 109 2. General Block Diagram ............110~111 3. Control Section ................ 112~120 3-1. Block Diagram ..............116 3-2. Reset Circuit ..............117 3-3. SRAM and RTC Back up Circuit ........118 3-4. Supervision circuit for the Thermal Head Temperature ..119 3-5.
Page 135: Connection Diagram
KX-FT21LA 1. CONNECTION DIAGRAM +24V JACK TO TEL LINE +24V +24V +24V +5VD TO EXT.TEL JACK +5VA BELL EXHOOK PAPER HOOK LATCH SPMUTE STB1 H/STX SPOUT H/SRX ANALOG BOARD CLOCK SPEAKER DIGITAL BOARD STR2 MOTOR OPESE SENSOR KIN0 KIN1 KIN2 KIN3 KSTAR V.LED...
Page 136: General Block Diagram
KX-FT21LA 2. GENERAL BLOCK DIAGRAM The control section will be explained as shown in the block diagram. ASIC (IC1) ....Composed mainly of an address decoder, modem control section, CPU and RTC. Controls the general FAX operations. Controls the operation panel I/F. Controls the thermal head I/F and CIS I/F.
Page 137 General Block Diagram OPERATION PANEL POWER SUPPLY AC120V SELE CTOR +24V SENSOR KEY MATRIX DIGITAL BOARD ANALOG BOARD +24V +24V LINE 3.3V MOS SW SRAM 256k EXT. RESET CODEC BELL PRINTER OP PANEL CONTROL HOOK SW ASIC HOOK PAPER PAPER MODEM IMAGE PROCESSING...
Page 138: Control Section
KX-FT21LA 3. CONTROL SECTION 1. ASIC (IC1) This custom IC is used for general FAX operations. CPU: This model uses a Z80 equivalent CPU operating at 6MHz. Many of the peripheral functions are handled by custom designed LSIS. As a result, the CPU only needs to process the result. RTC: Real time clock.
Page 139 KX-FT21LA Ground OPEN O Not used IOP92 3.3V OPEN O Not used IOP93 3.3V OPEN O Not used IOP94 3.3V OPEN O Not used IOP95 3.3V +3.3V 3.3V Pow er supply OPEN O Not used FMEMCS/IOP27 3.3V FMEMDO/IOP26 3.3V Not used O Not used FMEMDI/IOP25 3.3V...
Page 140 KX-FT21LA SP-MUTE XOPRBE/MUX/OP53 3.3V Speaker mute control OPEN O Not used XRAS/IOP42 3.3V OPEN O Not used XCAS1/IOP43 3.3V OPEN O Not used XCAS2/IOP44 3.3V 3.3V Data bus 3.3V Data bus 3.3V Data bus 3.3V Data bus 3.3V Data bus 3.3V Data bus 3.3V...
Page 141 KX-FT21LA OPEN O Not used STB4 MULT3/5 TH DATA O Thermal data THDAT MULT3/5 Ground MULT3/5 Pow er supply for THCLK, DAT, LAT, STB TH CLK O Thermal head clock THCLK MULT3/5 TH LAT O Thermal head latch THLAT MULT3/5 CIS SEL STBNP 3.3V...
Page 142: Block Diagram
KX-FT21LA 3-1. BLOCK DIAGRAM - 116 -...
Page 143: Reset Circuit
KX-FT21LA 3-2. RESET CIRCUIT The output from pin 1 of the Reset IC (IC4) resets the gate array (IC1). (1) During a power surge, a positive reset pulse of 175 msec or more is generated and the system is reset completely. This is done to prevent partial resetting and system runaway during a power fluctuation.
Page 144: Sram And Rtc Back Up Circuit
KX-FT21LA 3-3. SRAM and RTC BACK UP CIRCUIT (1) Function This unit has a lithium battery (BATT) which works for the RAM (IC3) and Real Time Clock (RTC,Integrated into ASIC:IC1). The user parameter for autodial numbers, the transmission ID, the system setup date and so on are stored in the RAM (IC3). The RTC continues functioning, even when the power switch is OFF, backed up by a lithium battery.
Page 145: Supervision Circuit For The Thermal Head Temperature
KX-FT21LA 3-4. SUPERVISION CIRCUIT FOR THE THERMAL HEAD TEMPERATURE (1) Function The thermistor changes the resistor according to the temperature and uses the thermistor's characteristics. The output of pin 193 of IC1 becomes a low level. Then when it becomes a high level, it triggers point A . In point C ,according to the voltage output time, the thermal head's temperature is detected.
Page 146: Led Array
KX-FT21LA 3-5. LED ARRAY(CIS) The LED ARRAY will light during transmission and copying as a light source to recognize document characters, patterns, or graphics on a document. It is also possible to light the LED ARRAY in the test mode. Circuit Diagram ABOUT 12V (LED OFF) +24V...
Page 147: Thermal Head
KX-FT21LA Block Diagram SYSTEM CONTACT IMAGE SENSOR ANALOG SIGNAL PROCESSING IMAGE SECTION PROCESSING SECTION MODEM THERMAL HEAD Analog Front/End (AFE) CONVERTER TEL.LINE - 121 -...
Page 148 KX-FT21LA 4-2. THERMAL HEAD (1) Function This unit utilizes state of the art thermal printer technology. The recording paper (roll paper) is chemically processed. When the thermal head contacts this paper it emits heat momentarily, and black dots (appearing like points) are printed on the paper. If this continues, letters and/or diagrams appear, and the original document is reproduced.
Page 149: Timing Chart
KX-FT21LA Circuit Diagram MAIN BOARD +24V THERMAL HEAD THON 192DOT 192DOT NO.19 NO.1 NO.2 THERMISTOR GATE ARRAY CLOCK (IC1) THLAT THLAT LATCH REGISTER LATCH REGISTER THDAT STROBE2 THDAT SHIFT REGISTER SHIFT REGISTER THCLK THCLK +24V STB1 STB2 +24V +24V LATCH STROBE1 AIN2 Timing Chart...
Page 150: Scanning Block
KX-FT21LA 4-3. SCANNING BLOCK The scanning block of this device consists of a control circuit and a contact image sensor made up of a celfoc lens array, an LED array, and photoelectric conversion elements. Circuit Diagram AIN1 173 CISON CISSEL +24V V.LED LED ON...
Page 151: Stepping Motor Drive Circuit
KX-FT21LA 4-4. STEPPING MOTOR DRIVE CIRCUIT (1) Function One individual stepping motor is used for transmission and reception. It feeds the document or recording paper synchronized for reading or printing. (2) Circuit Operation During motor drive, gate array IC1 pin 153 becomes a high level, and Q14 and Q7 go ON as a result. +24 V is supplied to the motor coil.
Page 152: Gear Section
KX-FT21LA 4-5. GEAR SECTION This section shows how the motor-driven gear mechanism works in the main operations: FAX transmission, FAX reception the motor and copying. 4-5-1. Mode Selection When the motor attached to the Drive Motor Gear(G7) rotates counterclockwise (CCW), Swing Gear A-2 engages the CAM and CAM turns counterclockwise to select a mode.
Page 153 KX-FT21LA 4-5-2. Mode Operation Once a mode is selected, the Drive Motor Gear rotates clockwise (CW) and then the Swing Gear A-1 controls the mode operation. A: Transmit mode Swing Gear A-1 engages G6 and conveys its drive power to the Separation Roller Gear for pre-feeding documents. B: Receive mode Swing Gear B engages G8 and conveys its drive power to the Platen Roller Gear for printing the received data.
Page 154 KX-FT21LA 2. Scanning When the document is set, in the paper tray does the Document Sensor See 3-11. Sensor Section (page 77.) (PS1) turn ON ? The motor rotates CW and the document is pre-fed. Press the dial key. Press the start key. Does the motor rotate CW and is the Error is displayed.
Page 155 KX-FT21LA 4. Copying When the document is set in the paper tray, does See 3-11. Sensor Section (page 77.) the Document Sensor (PS1) turn ON ? The motor rotates cw and the document is pre-fed. Press the start key. The motor rotates cw and the Read Position Sensor (PS2) is ON.
Page 156: Sensor And Switches
KX-FT21LA 4.6 SENSORS AND SWITCHES All of the sensor and switches are shown below. Sensor or Switch name Sensor Circuit Sensor Location ----- Digital MOTOR Position Cover Open and • uCHECK COVER•vand Analog Paper Set • uOUT OF PAPER• v ----- Hook SW Document...
Page 157 KX-FT21LA [Motor Position Sensor] This sensor is a detection switch for recording the position of the CAM. Digital Board Signal (IC1-174 Pin) Home position Low level Other High level [Recording Paper Sensor (SW1) ] When there is no recording paper, the plate is separated from the switch lever and the switch turns off. Pin 9 of CN1 (Analog board) becomes a high level.
Page 158 KX-FT21LA [Read Position Sensor (PS2) ] When a document is brought to the read position, the shelter plate passes the sensor light, the phototransistor becomes ON, and the input signal of the CN2-3 pin (Operation) becomes a low level. When there is no document at the read position, the shelter plate closes the sensor light, the phototransistor becomes OFF, and the input signal of the CN2-3 pin (Operation) becomes a high level.
Page 159: Modem Section
KX-FT21LA 5. MODEM SECTION 5-1. FUNCTION The unit uses a 1 chip modem (IC11), enabling it to act as an interface between the control section for FAX sending and receiving, and the telephone line. During a sending operation, the digital image signals are modulated and sent to the telephone line.
Page 160 KX-FT21LA (4) Concerning Transmission Time Transmission Time = Control Time Image Transmission Time Hold Time Transmission time consists of the following. Control time : This is time at the start of transmission when the functions at the sending and receiving sides are confirmed, the transmission mode is established, and transmission and reception are synchronized.
Page 161: Function
KX-FT21LA (6) Explanation of Technology 1.G3 Communication Signals (T. 30 Binary Process) For G3 facsimile communication, this is the procedure for exchanging control signals between the sending and receiving machines both before and after transmission of image signals. Control signals at 300 bps FSK are: 1850 Hz...0, 1650Hz...1. An example of the binary process in G3 communication is shown below.
Page 162 KX-FT21LA Bit No. DIS/DTC Reserved for future T.3 operation features. Reserved for future T.3 operation features. Transmitter - T.4 operation Receiver - T.4 operation Receiver - T.4 operation Data signaling rate Data signaling rate 11, 12 V.27 ter fallback mode 2400 bit/s V.27 ter (0, 0) V.27 ter...
Page 163 KX-FT21LA Bit No. DIS/DTC Standard setting Extend field Extend field 2400 bit/s handshaking 2400 bit/s handshaking Uncompressed mode Uncompressed mode Error correction mode Error correction mode Frame size 0 = 256 octets Set to "0" 1 = 64 octets Error limiting mode Error limiting mode Reserved for G4 capability on PSTN Reserved for G4 capability on PSTN...
Page 164 KX-FT21LA Signal Identification Signal Format Function Refer to the next page. Image Signal Sends 12 bits (0...01 • ~ 6 times) to the receiver at the same speed as the image signal and notifies completion (Return to Control) of the first sheet. End of one communication X1110100 (End of Procedure)
Page 165: Modem Circuit Operation
KX-FT21LA 5-2. MODEM CIRCUIT OPERATION The ASIC (IC1) has all the hardware satisfying the ITU-T standards mentioned previously. The modem is included in IC1. The signal communicates with the TEL line through the analog front end IC (IC5) of digital/ analog, analog/digital convertor.
Page 166 Analog Unit Block Diagram RLY1 POS1 +24V LINETX RLY1 LINE-RLY LINERX Analog Board BELL Digital Board Analog Front End (IC5) MTX ENB MOM RX ENB HANDSET TEL RX ENB H/STX H/STX MUTE H/SRX H/SRX ENB ASIC (IC1) SPEAKER SP AMP SPOUT HOOK PAPER...
Page 167: Ncu Section
KX-FT21LA 6. NCU Section 6-1. GENERAL This section is the interface between the telephone line and external telephone. It is composed of an EXT. TEL Line re- lay (RLY1), bell detection circuit, EXT TEL selection circuit, pulse dialing circuit, line amplifier, sidetone circuits and mul- tiplexer.
Page 168 KX-FT21LA 6-4. LINE AMPLIFIER AND SIDE TONE CIRCUITS (1) Circuit Operation The reception signal received as output from line transformer T1 is given as input to C14, R13 and IC2 pin(2). Then it is input to the reception system at an amplifier gain of 5.9 dB from pin(2). The transmission signal is input from CN1 pin (11), and output to the TEL line through C6, R14 and T1.
Page 169: Its And Monitor Section
KX-FT21LA 7. ITS (Integrated telephone System) and MONITOR SECTION 7-1. GENERAL During the monitor operation, the speaker output passes through the power amplifier (IC1) [Analog board]. The DTMF signal is output from the modem (IC1: digital board). The alarm tone, the key tone, bell tone, and beep are output from gate array IC1 (digital board).
Page 170: Ext.tel
KX-FT21LA 8. EXT. TEL EXT. TEL JACK is provided for the external TEL connection. Connect the telephone to the EXT. TEL JACK. Because the unit (FT21) has the priority, EXT. TEL is disconnected when the unit is OFF-HOOK. (1) EXT. TEL DC LOOP (Signal Path) T CN4 (3) POS1 J8 RLY1 (3-5)
Page 171 Circuit Diagram +5VA R11 C10 +2.0V POS1 RLY1 +5VD +24V Analog Board Digital Board CN1(10) CN2(10) To IC5...
Page 172: Operation Panel
KX-FT21LA 9. OPERATION PANEL The unit consists of an LCD (Liquid crystal display), KEYs, photo interrupters (sensor), and analog switches (for key scan). The key scan (analog switch control, reading), sensor detection (sensor control, reading) and LCD control are all controlled by I/O of ASIC (IC1) on the digital board.
Page 173 KX-FT21LA 9-2. SENSOR DETECTION When CN1(8) (OPSEL) is "L", the detection of the document sensor and read start position sensor are available. 9-3. LCD CONTROL "KTXD", "KSCLK", "KLATCH" and "KSTART" are sent as D4~D7 to control the LCD. D4~D7 - 147 -...
Page 174: Power Supply Switching Board Section
KX-FT21LA 10. POWER SUPPLY SWITCHING BOARD SECTION Block Diagram Input Input Rectifier Circuit C106 Output Over Circuit Kick-on R102 Circuit Voltage Voltage Circuit Circuit R103 Converter Circuit R104 Surge Output absorber A-B Voltage Wave Form Circuit circuit C-D Voltage Wave Form Control Circuit Over...
Page 175 KX-FT21LA Using a different winding ratio results in the voltage function given by the formula in figure (c). As you can see, it is possible to keep V constant by changing the ratio of T and T in response to variations in input voltage.
Page 176 KX-FT21LA [Surge Absorber Circuit] This circuit is for absorbing surge voltage generated by the transformer. [Control Circuit and Detecting Circuit] The control circuit amplifies the output with increased voltage detected in the error detecting circuit. Then it drives the main transistor. In this power supply, the duty ratio is defined by changing the ON period of the main transistor.
Page 177 KX-FT21LA • ¡ FOR THE SCHEMATIC DIAGRAM 1. DC voltage measurements are taken with an oscilloscope or a tester with a ground . 2. The schematic diagram and circuit board may be modified at any time with the development of new technology.
Page 178 KX-FT21LA MEMO - 152 -...
Page 179 KX-FT21LA KX-FT21LA PRINTED CIRCUIT BOARD (DIGITAL BOARD) (BOTTOM VIEW) (for PFUP1147ZA) PFUP1147Z - 153 -...
Page 180 KX-FT21LA KX-FT21LA PRINTED CIRCUIT BOARD (DIGITAL BOARD) (COMPONENT VIEW) (for PFUP1147ZA) AUTO -CH R101 PFUP1147Z 3.3V RA1 RA2 R102 R103 R104 L13 L14 TEST RESET AMON VIDEO TP11 - 154 -...
Page 181 KX-FT21LA KX-FT21LA PRINTED CIRCUIT BOARD (DIGITAL BOARD) (BOTTOM VIEW) (for PFUP1147ZB) PFUP1147Z - 155 -...
Page 182 KX-FT21LA KX-FT21LA PRINTED CIRCUIT BOARD (DIGITAL BOARD) (COMPONENT VIEW) (for PFUP1147ZB) AUTO -CH R101 PFUP1147Z 3.3V RA1 RA2 R102 R103 R104 L13 L14 TEST RESET AMON VIDEO TP11 - 156 -...
Page 183 KX-FT21LA KX-FT21LA SCHEMATIC DIAGRAM (DIGITAL CIRCUIT) CIS LED ARRAY ON: 3.3V OFF: 0V 3.3V MOTOR ON: 3.3V PRINTING OFF: 0V 23~24V PRINTING 3.3V DATA LATCH CLOCK STB1 STB2 THERMAL HEAD TEMP WATCH DOG ERROR 5V (NORMAL) 0V (WATCH DOG ERROR OCCUR) - 157 -...
Page 184 KX-FT21LA KX-FT21LA SCHEMATIC DIAGRAM (ANALOG CIRCUIT) FAX TX FAX RX, TEL TALK FAX RX BELL DETECT FAX RX, HANDSET TX LINE ON/OFF, DIALPULSE 3.3V 2.1V NO PAPER: 5V PAPER: 0V ON-HOOK: 5V OFF-HOOK: 0V - 158 -...
Page 185 KX-FT21LA KX-FT21LA PRINTED CIRCUIT BOARD (ANALOG BOARD) (COMPONENT VIEW) PFUP1148Z AUTO-CH PCB-CH - 159 -...
Page 186 KX-FT21LA KX-FT21LA PRINTED CIRCUIT BOARD (ANALOG BOARD) (BOTTOM VIEW) PFUP1148Z - 160 -...
Page 187 KX-FT21LA KX-FT21LA PRINTED CIRCUIT BOARD (SWITCHING POWER SUPPLY) (COMPONENT VIEW) (BOTTOM VIEW) SRF912UC CAUTION FOR CONTINUED PROTECTION AGAINST RISK OF MITSUMI ELEC. CO., LTD. FIRE. REPLACE ONLY WITH 68-4492A SAME TYPE AC125V 5A 7694V-0 CN31 AC125V 5A 94V-0 RATINGS OF FUSE. F101 R111 F101...
Page 188: Schematic Diagram (Switching Power Supply)
KX-FT21LA KX-FT21LA SCHEMATIC DIAGRAM (SWITCHING POWER SUPPLY) 300V -0.8V Cycle=2.2 s T101 TRANS CN301 Cycle=2.2 s D201 D102 D101 C202 D103 D104 1000p R105 G R223 C205 Q101 1/50 D107 Q102 R107 R106 C109 ZNR102 470V 100/2 100/2 0.01 C102 C110 R108 C103...
Page 189 KX-FT21LA KX-FT21LA PRINTED CIRCUIT BOARD (OPERATION BOARD) (COMPONENT VIEW) (BOTTOM VIEW) - 163 -...
Page 190 KX-FT21LA KX-FT21LA SCHEMATIC DIAGRAM (OPERATION CIRCUIT) KEY SCAN 0V SENSOR SCAN 5V OV/3.3V/5V NO PAPER 0V Read Document PAPER 5V sensor position sensor - 164 -...
Page 191 KX-FT21LA TERMINAL GUIDE OF IC'S TRANSISTORS AND DIODES PQVICM4051BF PFVIT7E05 PFVIXCN4202N PFVITC35133F PFVIBA10358F PFVIBA12003 PQVIMC34119M PFWIFT21LA PFVIGM6256FF PQVINJM4558M 2SC1740S PFVIBU4066BF Anode Cathode Cathode Anode PQVTDTC143E PQVTDTC114EU MA165 2SB1322 MA2300 2SK2640 2SC4155R, 2SC4155S Cathode Anode Cathode Anode Anode Cathode Cathode Anode MA4030 MA7200, PFVD1N4005 PFVDRMRLS245...
Page 192: Fixtures And Tools
KX-FT21LA FIXTURES AND TOOLS - 166 -...
Page 193: Cabinet, Mechanical And Electrical Parts Location
KX-FT21LA CABINET, MECHANICAL AND ELECTRICAL PARTS LOCATION 1. OPERATION PANEL SECTION PCB3 - 167 -...
Page 194 KX-FT21LA 2. UPPER CABINET SECTION - 168 -...
Page 195 KX-FT21LA 3. LOWER CABINET /P.C.B. SECTION PCB2 PCB4 Refer to PCB1 - 169 -...
Page 196 KX-FT21LA 4. MOTOR SECTION Note: Make sure that Gears 1, 2 and 3 are installed face up. (The product number is put on the face.) - 170 -...
Page 197 KX-FT21LA 5. ACTUAL SIZE OF SCREWS AND WASHER Part No. Illustration XTW3+S10P XSB4+6 XSN3+W6FZ - 171 -...
Page 198 KX-FT21LA ACCESSORIES AND PACKING MATERIALS - 172 -...
Page 199: Pfgv1009Z Cover, Tel Card
KX-FT21LA REPLACEMENT PARTS LIST This replacement parts list is for the KX-FT21LA only. Ref . No. Part No. Part Name & Description Model KX-FT21LA PFDG1123Z GEAR, PLATEN Notes: PFHG1064Z SEPARATION RUBBER 1. The marking (RTL) indicates that the Retention Time is limited f or this item. PFDE1101Z LEVER, ADJUSTMENT Af ter the discontinuation of this assembly in production, the item will...
Page 200: Pfjq1015Z Motor
KX-FT21LA This replacement parts list is for the KX-FT21LA only. Ref . No. Part No. Part Name & Description Ref . No. Part No. Part Name & Description & Value DIGITAL BOARD PARTS (4. GEAR CHASSIS SECTION) PCB1 PFWP1FT21LA DIGITAL BOARD ASS'Y (RTL) PFJQ1015Z MOTOR PFMH1069Z...
Page 201: Cn1 Pqjp8G30Y Connector, 8Pin
KX-FT21LA This replacement parts list is for the KX-FT21LA only. Ref . No. Part No. Part Name & Description & Value Ref . No. Part No. Value (CONNECTORS) ERJ3GEY J473 ERJ3GEY J433 PQJP8G30Y CONNECTOR, 8PIN ERJ3GEY J224 220K PQJP16A19Z CONNECTOR, 16PIN ERJ3GEY J395 3.9M PQJP5G30Y...
Page 202 KX-FT21LA This replacement parts list is for the KX-FT21LA only. Ref . No. Part No. Part Name & Description & Value Ref . No. Part No. Part Name & Description ECUV1H104ZFV ANALOG BOARD PARTS ECUV1H104ZFV ECUV1H104ZFV PCB2 PFLP1198BXZA ANALOG BOARD ASS'Y (RTL) ECUV1H100DCV ECUV1H150JCV ECUV1H102KBV...
Page 203 KX-FT21LA This replacement parts list is for the KX-FT21LA only. Ref . No. Part No. Part Name & Description & Value Ref . No. Part No. Value (RELAY ) (CAPACITORS) RLY 1 PFSL001Z RELAY ECUV1H103KBV 0.01 ECUV1H103KBV 0.01 ECUV1H152KBV 0.0015 (TRANSFORMER) ECUV1H104ZFV ECEA1HKS4R7...
Page 204 KX-FT21LA This replacement parts list is for the KX-FT21LA only. Ref . No. Part No. Part Name & Description & Value Ref . No. Part No. Part Name & Description & Value (RESISTORS) POWER SUPPLY BOARD PARTS ERJ3GEY 0R00 PCB4 PFLP1227MZL POWER SUPPLY BOARD ASS'Y ERDS1TJ470...
Page 205 KX-FT21LA This replacement parts list is for the KX-FT21LA only. Ref . No. Part No. Part Name & Description & Value R221 PQ4R10XJ681 R222 PQ4R10XJ472 4.7K R223 PQ4R10XJ101 R224 PQ4R10XJ223 R225 PQ4R10XJ123 R226 PQ4R10XJ222 2.2K (CAPACITORS) C101 ECQU2A104MV C102 ECQU2A104MV C103 ECKNTS222ME 0.0022...
Page 206 KX-FT21LA D (Q) KXFT21LA Printed in Japan - 180 -...

This manual is also suitable for:

Kx-ft21bx-w

Panasonic KX-FT21BX Service Manual

Table of Contents

Troubleshooting Guide

1 Troubleshooting Summary

2 User Recoverable Errors

3 Troubleshooting Details

4 Programming and Lists

5 Test Functions

6 Journal 3

Disassembly Instructions

Circuit Operations

1 Connection Diagram

2 General Block Diagram

3 Control Section

4 Facsimile Section

5 MODEM Section

6 NCU Section

7 ITS and Monitor Section

8 Ext.tel

9 Operation Panel

10 Power Supply Switching Board Section

Quick Links

Chapters

Troubleshooting

Related Manuals for Panasonic KX-FT21BX

Summary of Contents for Panasonic KX-FT21BX

This manual is also suitable for:

Table of Contents