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SERVICE MANUAL

VIDEO CASSETTE RECORDER

Sec. 1: Main Section

 Specifications

 Preparation for Servicing

 Adjustment Procedures

 Schematic Diagrams

 CBA’ s

Sec. 2: Deck Mechanism Section

 Standard Maintenance

 Alignment for Mechanism

 Disassembly/Assembly of Mechanism

 Alignment Procedures of Mechanism

PA L

Sec. 3: Exploded views 
and Parts List Section

 Exploded views

 Parts List

23C-250

23C-250A 

H7700CVR

Summary of Contents for 23C-250

Page 1: ...cing Adjustment Procedures Schematic Diagrams CBA s Sec 2 Deck Mechanism Section Standard Maintenance Alignment for Mechanism Disassembly Assembly of Mechanism Alignment Procedures of Mechanism PAL Se...

Page 2: ...Adjustment Instructions 1 6 1 Block Diagrams 1 7 1 Function Indicator Symbols 1 7 11 Schematic Diagrams CBA s and Test Points 1 8 1 Waveforms 1 9 1 Wiring Diagram 1 10 1 IC Pin Function 1 11 1 Lead Id...

Page 3: ...ode 3 2 Output R P dBV 9 6 1 5 SP Mode 3 3 S N R P dB 36 41 SP Mode 3 4 Distortion R P 1 0 4 0 SP Mode 3 5 Freq resp R P at 200Hz dB 11 4 SP Mode 20dB ref 1kHz at 8kHz dB 14 4 SP Mode 4 Tuner 4 1 Vide...

Page 4: ...ires covered with PVC tubing 2 Double insulated wires 3 High voltage leads D Use specified insulating materials for hazardous live parts Note especially 1 Insulation tape 2 PVC tubing 3 Spacers 4 Insu...

Page 5: ...prongs and externally exposed accessible parts RF terminals an tenna terminals video and audio input and output ter minals microphone jacks earphone jacks etc is lower than or equal to the specified...

Page 6: ...ck IC with tweezers while apply ing the hot air 3 Bottom of the flat pack IC is fixed with glue to the CBA when removing entire flat pack IC first apply soldering iron to center of the flat pack IC an...

Page 7: ...lat pack IC you can remove it easily Fig S 1 3 2 Affix the wire to a workbench or solid mounting point as shown in Fig S 1 5 3 While heating the pins using a fine tip soldering iron or hot air blower...

Page 8: ...potential difference caused by electro static charge during unpacking or repair work 1 Ground for Human Body Be sure to wear a grounding band 1M that is properly grounded to remove any static electri...

Page 9: ...Tape Start Sensor Tape End Sensor and Reel Sensors If these TPs are con nected before plugging in the unit the function of the sensors will stay valid See Fig 1 Note Because the Tape End Sensors are...

Page 10: ...en slowly lift the Deck Assembly up Lifting Deck As sembly disconnects five Connectors CN251 CN501 CN503 CN504 CN506 Fig 5 3 When reassembling the unit always reinsert Lock ing Tabs L 4 and then reins...

Page 11: ...mbly S 3 S 4 CN501 CN504 CN251 CN506 CN503 Spacer Fig 5 L 2 L 1 2 Front Assembly L 2 4 Function C B A Fig 2 L 3 Lift PCB up and over tab 4 Function CBA CN505 8 Main CBA Fig 4 3 Jack CBA S 2 S 2 S 2 CN...

Page 12: ...8 Main C B A SW507 LD SW LD SW Pin Hole Hole Shaft Cam Gear 8 Main C B A 5 Deck Assembly Triangle Marks Fig 7 S 5 L 4 L 4 8 Main C B A Fig 6 1 5 3 H8740DC...

Page 13: ...probe V Range 0 001 50V Div F Frange AC DC 20MHz 2 Alignment Tape FL6A 1 Head Switching Position Adjustment Purpose To determine the Head Switching point dur ing playback Symptom of Misadjustment May...

Page 14: ...EMORY IC505 DRUM LOADING MOTOR DRIVE IC506 IC503 Servo System Control Block Diagram BLOCK DIAGRAMS END S END S T REEL ST S Q503 Q504 Q501 RESET SW508 RESET Q506 S REEL 50 C POW SW 46 SW POINT AL 5V VR...

Page 15: ...C COMB ACC B UP AMP MAIN CONV R R P P R P SUB CONV 4 43MHz 629KHz 21 24 23 20 IC301 IC501 Y C PROCESS 29 67 66 49 X302 4 43MHz 43 45 46 41 Q307 REC VIDEO SIGNAL PB VIDEO SIGNAL MODE SP REC BUFFER Q30...

Page 16: ...81 A OUT 7 A PB REC CN504 6 A COM 4 AE H 5 FE H A PB REC 4 A COM 3 AE H 1 AE H FE H 2 CN287 AUDIO HEAD AUDIO ERASE HEAD ACE HEAD ASSEMBLY FE HEAD 1 FE H 2 FE H GND CN501 1 7 5 1 7 6 H8743BLA MAIN CBA...

Page 17: ...e that all components in the power supply circuit are not defective before you connect the AC plug to the AC power supply Otherwise it may cause some components in the power supply circuit to fail H87...

Page 18: ...BUF BUF BUF AMP AMP 6dB 6dB DRIVE A B SW1 A SW2 B C A SW3 B C JK101 V OUT V IN V OUT V IN DEC L A OUT A IN A OUT A IN A OUT A IN A OUT A IN 1 2 3 6 JK101 1 2 3 6 JK102 19 20 JK102 8 JK102 IC101 INPUT...

Page 19: ...ON PWR ON REC REC ON REC PAUSE REC Blinks at 0 8Hz interval T REC OTR ON T REC OFF T REC incomplete Blinks at 0 8Hz interval When reel and capstan mechanism is not functioning correctly No 1 Blinks at...

Page 20: ...C SR 15 20 C 25 85 C Z 30 80 20 C 10 70 C Note 1 Do not use the part number shown on these draw ings for ordering The correct part number is shown in the parts list and may be slightly different or am...

Page 21: ...which are listed with their part numbers in the parts list section of the service manual 4 Wire Connectors 1 Prefix symbol CN means connector can disconnect and reconnect 2 Prefix symbol CL means wire...

Page 22: ...1 8 3 1 8 4 1 8 5 H8624SCM1 Main 1 4 Schematic Diagram...

Page 23: ...1 8 6 1 8 7 1 8 8 H8624SCM2 Main 2 4 Schematic Diagram...

Page 24: ...1 8 9 1 8 10 1 8 11 H8624SCM3 Main 3 4 Schematic Diagram...

Page 25: ...1 8 12 1 8 13 1 8 14 H8624SCM4 Main 4 4 Schematic Diagram Function Schematic Diagram H8743SCF...

Page 26: ...1 8 15 1 8 16 Jack Schematic Diagram H8622SCJ...

Page 27: ...1 8 17 1 8 18 SECAM Schematic Diagram H8624SCS...

Page 28: ...CIRCUIT A VARIABLE ISOLATION TRANSFORMER IS REQUIRED NOTE THE VOLTAGE FOR PARTS IN HOT CIRCUIT IS MEASURED USING HOT GND AS A COMMON TERMINAL CAUTION FOR CONTINUED PROTECTION AGAINST FIRE HAZARD REPLA...

Page 29: ...REQUIRED NOTE THE VOLTAGE FOR PARTS IN HOT CIRCUIT IS MEASURED USING HOT GND AS A COMMON TERMINAL CAUTION FOR CONTINUED PROTECTION AGAINST FIRE HAZARD REPLACE ONLY WITH THE SAME TYPE FUSE CAUTION Fixe...

Page 30: ...1 8 26 1 8 25 BH8700F01031 Function CBA Top View Function CBA Bottom View...

Page 31: ...1 8 28 1 8 27 BH8700F01021 Jack CBA Top View Jack CBA Bottom View...

Page 32: ...1 8 30 1 8 29 SECAM CBA Top View SECAM CBA Bottom View BH8700F01011 C...

Page 33: ...usec 50mV x 10 WAVEFORMS TP751 of Main CBA WF1 UPPER WF2 LOWER V OUT 0 1V x 10 RF SW 0 5V x 10 50usec TP751 of Main CBA TP302 of Main CBA WF5 C PB 10mV x 10 RF SW 0 5V x 10 5msec UPPER LOWER WF2 TP302...

Page 34: ...REC CTL CTL 6 5 4 3 2 1 CN287 M LOADING MOTOR LOADING MOTOR ASSEMBLY CYLINDER ASSEMBLY 5 D COM 4 D U 3 LD M 1 LD M 2 GND 3 AE H 4 AE H FE H 5 A COM 6 A PB REC 7 CTL 8 CTL 9 CN506 PG IN D V 2 D W 1 V L...

Page 35: ...SW HiFi Audio Head Switching Pulse H L 19 OUT REC CTL Record Control Signal H L 20 OUT REC CTL Record Control Signal H L 21 IN C SYNC Composite Synchronized Pulse PULSE Pin No IN OUT Signal Name Funct...

Page 36: ...L L 66 OUT C F R Capstan Motor FWD REV Control Signal L Pin No IN OUT Signal Name Function Active Level 67 IN POW SAF P ON Power Detection Input Signal A D 68 IN END S Tape End Position Detect Signal...

Page 37: ...OUT Signal Name Function Active Level 98 OUT P6 Display Segment H L 99 N U Not Used 100 N U Not Used Notes Abbreviation for Active Level PWM Pulse Wide Modulation A D Analog Digital Converter 1 11 3...

Page 38: ...3199 Y GR BL 2SC2785 J H F K 2SC2058 Q KRA103M KRC103M DTC124ESA 2SA1015 GR TPE2 DTA124ESA BN1L4M T KRA104M DTA144ES 2SD1246 S T KTA1267 Y GR 2SA1175 J H F 2SC1815 Y TPE2 2SC1815 GR TPE2 2SC3331 T U 2...

Page 39: ...1 Disassembly Assembly Procedures of Deck Mechanism 2 4 1 Alignment Procedures of Mechanism 2 4 9 DECK MECHANISM SECTION VIDEO CASSETTE RECORDER 23C 250 23C 250A Sec 2 Deck Mechanism Section Standard...

Page 40: ...3 B574 Reel S Reel T B37 Capstan Motor B52 Cap Belt B73 FE Head B133 Idler Assembly B410 Pinch Arm A Assembly B414 M Brake S Assembly B416 M Brake T Assembly B525 LDG Belt Notes 1 Clean all parts for...

Page 41: ...but since it is very thin avoid cleaning it verti cally 2 Wait for the cleaned part to dry thoroughly before operating the unit 3 Do not reuse a stained head cleaning stick or a stained chamois cloth...

Page 42: ...L6NS8 2speed only Azimuth and X Value Adjustment of Audio Control Head Adjustment of Envelope Waveform J 2 Guide Roller Adj Screwdriver FSJ 0006 Guide Roller J 3 Mirror FSJ 0004 Tape Transportation Ch...

Page 43: ...guide preparations are in the Eject Position 4 Turn the LDG Belt in the appropriate direction shown in Fig M1 until the Moving guide prepara tions come to the Eject Position Stop turning when the pre...

Page 44: ...the tape is not creasing and that there is no slack on the supply and take up side Guide Rollers Use a blank tape Adjust the height of the Guide Rollers Supply side and take up side Use a blank tape...

Page 45: ...apparent adjust the Tilt Adj Screw of the AC Head Fig M6 1 B X Value Alignment Purpose To align the Horizontal Position of the Audio Con trol Erase Head Symptom of Misalignment If the Horizontal Posit...

Page 46: ...ght of Guide Roller 2 Refer to Fig M3 so that the waveform looks like the one shown in Fig M9 4 If the envelope is as shown in Fig M8 adjust the height of Guide Roller 3 Refer to Fig M3 so that the wa...

Page 47: ...embly T DM1 DM6 3 S 5 Two Connectors 8 8 Loading Motor Assembly T DM1 DM7 2 S 6 S 7 LDG Belt ACH Connector AN 9P and 9B 9 1 Tape Guide Assembly T DM1 DM8 P 2 C 8 10 1 Door Opener B T DM1 DM8 S 8 L 2 1...

Page 48: ...K RELEASE UNPLUG DESOLDER ADJUSTMENT CONDITION 34 33 TR Gear A B B DM1 DM14 35 34 FF Arm HI T DM1 DM14 36 28 Sensor Gear B DM1 DM15 C 7 37 28 Idler Assembly B DM1 DM15 38 28 BT Arm B DM2 DM15 P 5 39 2...

Page 49: ...39 20 21 40 27 28 24 30 29 26 31 32 38 22 Fig DM2 Bottom View 13 12 10 9 11 7 53 54 8 37 47 36 45 46 16 49 48 50 41 15 14 43 44 42 35 34 Fig DM1 Top View 2 4 3 H8743DA...

Page 50: ...A Slots Pin C Pin B Pin D Locking tab View for A Pull up Slide Slot A Slot A First while pushing the locking tab as shown in the right slide and pull up the right side on 2 to release Pin A and Pin B...

Page 51: ...9 18 17 19 S 12 L 7 After removing the Screw S 12 while pressing the Locking Tab L 7 remove 17 Fig DM10 10 12 11 9 S 8 L 2 P 3 P 2 Adj Screw C 8 Pin of 11 Pin of 9 Grooves of 31 31 When reassembling 9...

Page 52: ...in the left figure and then install 26 while pressing the spring P 4 to the direction of the arrow in the left figure and confriming that the position of the spring P 4 is placed as shown in the left...

Page 53: ...eassembling 31 meet the first groove on 31 to the first tooth on 51 as shown 31 Top View First tooth on 51 First groove on 31 Pin of 41 Pin of 38 Position of Mode Lever when installed Pin of 42 Align...

Page 54: ...48 49 S 17 Slide Holder S Slide Holder T S 18 50 L 3 Fig DM17 52 51 Slide P 9 Fig DM18 2 4 8 H8743DA...

Page 55: ...l or electrical parts Alignment points in Eject Position Alignment 1 Loading Arm S and T Assembly Install Loading Arm S and T Assembly so that their triangle marks point to each other as shown in Fig...

Page 56: ...ck Assembly so that the first tooth on the gear of the Rack Assembly meets the first groove on the Cam Gear A as shown in Fig AL4 Cam Gear A First tooth First groove on the Cam Gear A Alignment 3 Top...

Page 57: ...1 Mechanical Parts List 3 2 1 Electrical Parts List 3 3 1 Deck Parts List 3 4 1 EXPLODED VIEWS AND PARTS LIST SECTION VIDEO CASSETTE RECORDER 23C 250 23C 250A Sec 3 Exploded views and Parts List Secti...

Page 58: ...EXPLODED VIEWS Front Panel A1X 3 1 1 H8743FEX...

Page 59: ...quence 2B4 FUNCTION CBA A4 A7 A3 A10 2L061 2L061 2L061 2L061 2L032 2L012 JACK CBA JW751 A5 2B18 2L011 2L011 2L011 2L011 A2 2L011 2B18 1B1 2L021 2L021 2L032 2L021 2L051 2L021 2L021 2B43 2B44 MAIN CBA 2...

Page 60: ...Packing Some Ref Numbers are not in sequence S2 S2 X4 S1 X1 X2 X20 X3 Unit S3 3 1 3 H8740PEX...

Page 61: ...ssembly Bottom View Grease Point Chassis Assembly Top View Grease Point B35 B550 B410 B411 B494 L1471 B567 L1053 B74 B10 L1191 B73 L1463 B523 B9 B12 B492 B11 B571 B37 B126 B122 L1466 B501 B8 B121 B426...

Page 62: ...68 B572 B513 B502 B570 B491 B565 B417 L1151 B525 B3 B522 B524 Motor PCB Ass y B31 L1406 B148 B521 B520 B416 B518 B564 B556 B487 B573 B574 B499 B27 B508 B414 B404 B403 B558 B557 B581 B583 B580 B582 B57...

Page 63: ...in sequence B561 B303 B514 B555 B563 B300 B562 B313 B482 B355 B354 B319 B472 B483 B425 L1461 L1341 L1341 L1483 L1321 B347 L1321 Mark Description Part No Floil G 374G 0VZZ00109 Blue grease Deck Mechani...

Page 64: ...RTH PLATE CONV H2660BD 0VM409009B 2B7 SHIELD ASSEMBLY H8700EP See Electrical Parts List 2B8 BUSH LED F H3700UD See Electrical Parts List 2B18 FIBER TOP CASE H8101BD U15 PAL 0VM408394 2B22 SHEILD CYLIN...

Page 65: ...TIC CAP 220 F 6 3V M CE0KMASTL221 C056 CERAMIC CAP AX F Z 0 047 F 16V CCA1CZTFZ473 C252 CHIP CERAMIC CAP B K 1000pF 50V or CHD1JKB0B102 CHIP CERAMIC CAP B K 1000pF 50V CHD1JK30B102 C253 ELECTROLYTIC C...

Page 66: ...CHD1JZB0F104 CHIP CERAMIC CAP F Z 0 1 F 25V or CHD1EZB0F104 CHIP CERAMIC CAP F Z 0 1 F 50V or CHD1JZ30F104 Ref No Description Part No CHIP CERAMIC CAP F Z 0 1 F 25V CHD1EZ30F104 C372 CHIP CERAMIC CAP...

Page 67: ...MIC CAP B K 0 022 F 50V or CHD1JKB0B223 CHIP CERAMIC CAP B K 0 022 F 25V or CHD1EKB0B223 Ref No Description Part No CHIP CERAMIC CAP B K 0 022 F 50V or CHD1JK30B223 CHIP CERAMIC CAP B K 0 022 F 25V CH...

Page 68: ...ERA1804 D012 RECTIFIER DIODE FR202 NDQZ000FR202 D013 RECTIFIER DIODE FR202 NDQZ000FR202 D014 SCHOTTKY BARRIER DIODE SB140 or NDQZ000SB140 SCHOTTKY BARRIER DIODE ERB81 004 AERB81004 D015 ZENER DIODE MT...

Page 69: ...IN TRANSISTOR KRA103M or NQSZ0KRA103M RES BUILT IN TRANSISTOR DTA124ESA QQSZDTA124ES Ref No Description Part No Q057 TRANSISTOR 2SB892 S or QQSS002SB892 TRANSISTOR 2SB892 T QQST002SB892 Q058 RES BUIL...

Page 70: ...HIP RES 1608 1 10W J 22k or RRXAJB5Z0223 CHIP RES 1608 1 16W J 22k or RRXGJR5Z0223 Ref No Description Part No CHIP RES 1608 1 10W J 22k RRXAJR5Z0223 R019 PCB JUMPER D0 6 P5 0 JW5 0T R020 CHIP RES 1608...

Page 71: ...CHIP RES 1608 1 16W J 1k or RRXGJR5Z0102 CHIP RES 1608 1 10W J 1k RRXAJR5Z0102 Ref No Description Part No R329 CHIP RES 1608 1 10W J 8 2k or RRXAJB5Z0822 CHIP RES 1608 1 16W J 8 2k or RRXGJR5Z0822 CH...

Page 72: ...21 CARBON RES 1 4W J 820 RCX4JATZ0821 R411 CHIP RES 1608 1 10W J 10k or RRXAJB5Z0103 Ref No Description Part No CHIP RES 1608 1 16W J 10k or RRXGJR5Z0103 CHIP RES 1608 1 10W J 10k RRXAJR5Z0103 R412 CH...

Page 73: ...0103 CARBON RES 1 4W J 10k RCX4JATZ0103 R543 CHIP RES 1608 1 10W 0 or RRXAZB5Z0000 Ref No Description Part No CHIP RES 1608 1 16W 0 or RRXGZR5Z0000 CHIP RES 1608 1 10W 0 RRXAZR5Z0000 R544 CHIP RES 160...

Page 74: ...Z0102 R852 CHIP RES 1608 1 10W J 1 5k or RRXAJB5Z0152 CHIP RES 1608 1 16W J 1 5k or RRXGJR5Z0152 CHIP RES 1608 1 10W J 1 5k RRXAJR5Z0152 R854 CHIP RES 1608 1 10W 0 or RRXAZB5Z0000 CHIP RES 1608 1 16W...

Page 75: ...TROLYTIC CAP 4 7 F 25V M CE1EMASTL4R7 C141 CHIP CERAMIC CAP B K 2200pF 50V or CHD1JKB0B222 CHIP CERAMIC CAP B K 2200pF 50V CHD1JK30B222 C142 ELECTROLYTIC CAP 4 7 F 25V M or CE1EMASDL4R7 ELECTROLYTIC C...

Page 76: ...P CSS5021 1001 1780260 JK102 SKIRT JACK 21P HRC 21V 02P or JXGL210RP001 SKIRT JACK 21P HXC1536 010011 or JSZZ000HD001 SKIRT JACK 21P CSS5021 1001 1780260 Ref No Description Part No Ref No Description...

Page 77: ...B512 REEL WASHER MK9 5 2 1 0 5 0VM410058 B513 PSCW 752605 MK10 0VM411516 B514 SCREW RACK MK10 0VM411535 B516 REEL WASHER MK9 5 2 1 0 5 0VM410058 B518 P S W CUT 1 6X4 0X0 5T 0VM408485A B520 T BRAKE SP...

Page 78: ...23C 250 23C 250A H8743FP Printed in Japan 2001 04 20 HO...

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