Panasonic TX-21GV1, Service Manual

Page 1: ...m 386mm Depth 485 2mm 367 5mm Net weight 24kg 13kg Specifications are subject to change without notice Weights and dimensions shown are approximate NOTE This Service Manual should be used in conjunction with the Z 421V Technical guide temperature 5 C 35 C operating 20 C 60 C storage temperature format standard tape width 12 65mm tape speed SP 23 39mm sec LP 11 70mm sec GENERAL max recording time w...

Page 2: ...inet part on the receiver such as screw heads aerials connectors control shafts etc When the exposed metallic part has a return path to the chassis the reading should be between 4M ohm and 20M ohm When the exposed metal does not have a return path to the chassis the reading must be infinite LEAKAGE CURRENT HOT CHECK 1 Plug the a c cord directly into the a c outlet Do not use an isolation transform...

Page 3: ...ws as shown in Fig 2 Fig 3 DISASSEMBLY 1 Remove the 2 cable ties shown in Fig 4 2 Remove the 7 connectors shown in Fig 5 Fig 2 Connectors Cable Ties Main Board Power Board CRT Board Focus Screen Fig 4 Screw Screw Screw Screw TX 21GV1 TX 14GV1 Fig 2 Fig 5 Fig 3 3 ...

Page 4: ...g 6 5 Remove earth strap shown in Fig 7 6 Lift top cover and remove main pcb 7 Remove the 5 screws as shown in Fig 8 8 Remove the head connector seal cover shown in Fig 8 9 Remove the 4 connectors shown in Fig 9 Earth strap Fig 7 Speaker Connector Screws Fig 6 Top Cover Fig 9 Connectors Screws Fig 8 Head Connector Seal Cover 4 Connectors ...

Page 5: ...DISASSEMBLY Cont 10 Remove the 5 screws shown in Fig 10 11 Release the 5 chassis frame clips shown in Fig 11 and remove the main P C B from the chassis frame Fig 10 Fig 11 Screws Screws Clips Clips 5 ...

Page 6: ...pe to P906 CRT Cathode RGB 3 Press the SCREEN key Adjust the screen volume on the FBT so that the highest black level voltage is 130V 5Vdc 150V 5Vdc Focus 1 Apply a RETMA Pattern signal Adjust FOCUS VOLUME on the FBT for optimum setting White Balance 1 Apply a Colour Bar Pattern signal Adjust the RGB UP DOWN key to obtain optimum WHITE BALANCE X Position Adjustment P2 and P3 1 Play DP 2 Test tape ...

Page 7: ...setting for white balance Red correction Optimum setting for white balance AGC Set Pattern generator with RF level 60 2dBuV 210 25MHz Connect oscilloscope to P101 Tuner AGC input Adjust AGC using Yellow Blue buttons until the voltage drops to 1 0Vdc 0 2Vdc below its maximum voltage Sub AGC Press this button to access SUB TUNER AGC adjustment Press once picture is displayed in colour Press twice pi...

Page 8: ...STEM that has the DRUM wrapped by the tape _ The Main PCB is separated from the Deck When assembling it is connected by the B B TYPE CONNECTOR _ The CAPSTAN MOTOR and DRUM MOTOR are directly connected to the MAIN PCB DECK ASSEMBLY DIAGRAM OF DECK ASSEMBLY TOP VIEW 1 EARTH BRACKET ASSEMBLY 9 IDLER PLATE TOTAL ASSEMBLY 17 A C HEAD TOTAL ASSEMBLY 2 FE HEAD 10 T MAIN BRAKE ASSEMBLY 18 T SLANT POLE ASS...

Page 9: ...CK BOTTOM VIEW 1 CAPSTAN MOTOR 5 REEL GEAR TOTAL ASSEMBLY 9 DRUM TOTAL ASSEMBLY 2 F L RACK 6 RECORD SAFETY LEVER 10 LOADING RACK ASSEMBLY 3 CONNECT PLATE 7 L LOADING ASSEMBLY 4 REEL BELT 8 R LOADING ASSEMBLY 9 10 2 9 7 1 8 4 5 3 6 Fig 13 ...

Page 10: ...ACEMENT FRONT LOADING ASSEMBLY REMOVAL NOTE The FRONT LOADING ASSEMBLY can be removed only in the eject position 1 Remove the two screws A0400 as displayed in fig 14 below 10 A0400 Fig 14 Front loading assembly separation ...

Page 11: ...of the arrow to separate it from the TOP PLATE and CASSETTE HOLDER ASSEMBLY 2 Remove the CASSETTE HOLDER ASSEMBLY 3 Remove the screw holding the PRISM LINK R and remove the PRISM LINK R from the F L BRACKET R 11 Disassembly of the front loading assembly Fig 15 Disassembly of the front loading bracket right Fig 16 ...

Page 12: ...e the LOADING LEVER ASSEMBLY by pressing the connected section of the LOADING LEVER ASSEMBLY in the direction of the arrows 7 Remove the SAFETY SPRING between the SAFETY LEVER and the CASSETTE HOLDER PLATE 8 Remove the RELEASE SPRING between the RELEASE LEVER and the SAFETY LEVER R 12 Disassembly of the top plate Fig 17 Disassembly of the cassette holder assembly Fig 18 ...

Page 13: ... three screws 1 fixing the DRUM TOTAL ASSEMBLY 2 Remove the EARTH BRACKET ASSEMBLY 2 3 Carefully lift the DRUM TOTAL ASSEMBLY 3 from the DECK MECHANISM taking care not to damage or touch the VIDEO HEAD 13 NOTE 1 After assembling the DRUM TOTAL ASSEMBLY confirm that the tape runs smoothly Refer to ADJUSTMENT OF THE TAPE TRANSPORTING SYSTEM 2 When assembling the EARTH BRACKET ASSEMBLY a 3x12 screw s...

Page 14: ... of the arrows Fig 21 CAUTION Take care not to get the GUIDE ROLLERS of the S T SLANT POLES stained with grease When reassembling please refer to Fig 22 14 Reel belt loading rack assembly right left loading assemblies supply and takeup slant pole assembly removal Fig 21 LOADING GEAR R LOADING GEAR L TRIANGLE MARK ON LOADING GEAR L NOTCH IN LOADING GEAR R CIRCULAR MARK ON LOADING GEAR R HOLE OF LOA...

Page 15: ...T ASSEMBLY from the MAINBASE 3 PINCH LEVER TOTAL ASSEMBLY REMOVAL 1 Remove the POLY WASHER 3 from the PINCH LEVER POST of the MAINBASE 2 Unhook the PINCH LEVER SPRING 4 from the hook of the MAINBASE 5 and remove the PINCH LEVER TOTAL ASSEMBLY 9 CAUTION Take care not to coat Grease Oil or other substances on the surface of the PINCH ROLLER CAM GEAR RELAY LEVER AND F L RACK REMOVAL 1 Remove the CAM ...

Page 16: ...ASE 8 3 Unhook the S SUB BRAKE SPRING 4 from the MAINBASE and remove the S SUB BRAKE LEVER ASSEMBLY 5 from the MAIN BASE 8 4 Unhook the T SUB BRAKE SPRING 6 from the MAINBASE and remove the T SUB BRAKE LEVER ASSEMBLY 7 16 Assembly of the cam gear and relay lever Fig 25 Assembly of the cam gear and front loading rack Fig 26 Supply and takeup main and sub brakes removal Fig 27 F L RACK DATUM HOLE OF...

Page 17: ...ng the TENSION BAND ASSEMBLY on the MAINBASE adjust the position of the TENSION POLE as shown in fig 30 Avoid getting GREASE OIL or foreign substances on the FELT of the BAND BRAKE Take care not to deform tab A when separating it 17 Adjustment of the tension pole position Fig 30 Tension band assembly removal Fig 28 Tension band assembly removal Fig 29 DATUM HOLE OF MAINBASE DATUM HOLE OF TENSION L...

Page 18: ...R 1 from the REEL GEAR POST 2 and remove the IDLER PLATE TOTAL ASSEMBLY 3 from the MAIN BASE 2 Remove the S T REEL TABLES 4 and two POLY SLIDERS 5 from the DECK MECHANISM CAUTION When disassembling or assembling the IDLER PLATE TOTAL ASSEMBLY take care not to bend it 18 Idler plate total assembly and supply and takeup reel tables removal Fig 32 Capstan motor removal Fig 31 ...

Page 19: ... direction of the arrow NOTE When removing the CONNECT PLATE with the F L RACK installed take care not to damage or bend the CONNECT PLATE After assembling or disassembling the REEL GEAR TOTAL ASSEMBLY take care not to get OIL GREASE or other substances on the REEL BELT Take care not to deform or break tab B Check the assembly state the operating state of the REEL GEAR TOTAL ASSEMBLY before assemb...

Page 20: ...the MAINBASE in the EJECT mode as shown in fig 35 2 Make sure that part A of the RELAY LEVER when assembled in the CONNECT PLATE is fully rotated to the left side of B of the MAINBASE and is touching boss C of the MAINBASE as shown in fig 36 CAM GEAR F L RACK DATUM HOLE OF CAM GEAR DATUM HOLE OF MAIN BASE Datum position of relay lever and cam gear Fig 36 20 Datum position of front loading rack and...

Page 21: ...f the CAM SWITCH are aligned with each other as shown in fig 37 4 Make sure that boss A of the PINCH LEVER TOTAL ASSEMBLY is positioned at point B of the CAM GEAR as shown in fig 38 21 TRIANLE MARKS MUST MEET EACH OTHER Datum position of cam switch triangular marks Fig 37 Datum position of pinch lever total assembly and cam gear Fig 38 ...

Page 22: ... those of the R LOADING ASSEMBLY so that the hole of the LOADING RACK ASSEMBLY aligns with the circular mark on the R LOADING ASSEMBLY as shown in fig 39 22 Datum position of loading rack assembly and right and left loading lever assembly Fig 39 R LOADING ASSEMBLY B CIRCULAR MARK OF R LOADING ASSEMBLY TRIANGULAR MARK ON L LOADING ASSEMBLY A L LOADING ASSEMBLY HOLE OF LOADING RACK LOADING RACK ASSE...

Page 23: ...e measuring result is not within this specification refer to the NOTE below or repeat TENSION POLE POSITION ADJUSTMENT Note If the measuring result is not within the specification change the TENSION SPRING position To decrease the result choose hook A Otherwise choose hook B Confirm that all three probes of the Tentelometer are in contact with the TAPE During this process do not touch any other pa...

Page 24: ... position TENSION POLE POSITION ADJUSTMENT 1 Change MECHANICAL MODE to PLAY MODE 2 Confirm that the datum hole of TENSION LEVER is aligned with the datum hole of the MAIN BASE To adjust turn the BAND BRAKE ADJUST CAP clockwise or anti clockwise until the two datum holes are aligned with each other 24 Tension pole position adjustment Fig 41 DATUM HOLE OF TENSION LEVER DATUM HOLE OF MAIN BASE BAND B...

Page 25: ...just the TAPE TRANSPORTING SYSTEM 25 CLEANING S T GUIDE ROLLER HEIGHT ADJUSTMENT A C HEAD AS ADJUSTMENT TILT ADJUSTMENT AUDIO AZIMUTH ADJUSTMENT A C HEAD ADJUSTMENT X POSITION ADJUSTMENT PLAYBACK PHASE ADJUSTMENT LINEARITY ADJUSTMENT DRUM ENTRANCE EXIT ENVELOPE FINE TUNING REVIEW PLAY CHANGING OPERATION CHECK AUDIO OUTPUT CHECK A C HEAD TILT HEIGHT ADJUSTMENT AUDIO AZIMUTH ADJUSTMENT X POSITION AD...

Page 26: ... 3 If TAPE wrinkle is observed at the S T GUIDE ROLLER adjust to remove occurrence of wrinkles ADJUSTMENT OF THE A C HEAD ASSEMBLY TILT ADJUSTMENT 1 Play back a T 120 TAPE and check the running condition of the TAPE at the lower flanges of the T GUIDE POST ASSEMBLY see fig 42 2 Adjust the A C HEAD TILT SCREW until the TAPE runs stable as shown in fig 43 26 The schematic diagram of tape transportin...

Page 27: ...EIGHT ADJUSTMENT OF A C HEAD 1 Play back a T 120 TAPE 2 Make sure that the gap is 0 25mm between the lower end of TAPE and that of A C HEAD Fig 45 3 When the gap is larger than 0 25mm turn the A C HEAD HEIGHT ADJUST NUT anti clockwise When the gap is smaller than 0 25mm turn it clockwise Repeat this procedure until 0 25mm is obtained Audio control head assembly adjustment Height adjustment Fig 45 ...

Page 28: ... ALIGNMENT 3 Connect channel 1 scope probe to S W PULSE TEST PIN of PATH ADJ JIG 4 Connect channel 2 scope probe to ENVELOPE TEST PIN of PATH ADJ JIG 5 Turn the VR CONTROL to the centre point If the VR CONTROL is completely turned anti clockwise it is positioned on another tracking centre 6 With the VR CONTROL in the centre state turn the ADJUST BOSS by using a FLAT TYPE SCREW DRIVER and adjust th...

Page 29: ...D switching noise or vertical jitter may occur 1 Connect the PATH ADJ JIG to PTO1 of the MAIN CIRCUIT BOARD 2 Play the ALIGNMENT TAPE COLOUR BAR SIGNAL OR MONOSCOPE SIGNAL 3 Connect the channel 1 scope probe to the S W PULSE TEST PIN of the PATH ADJ JIG 4 Connect the channel 2 scope probe 1V div to the VIDEO OUT of the MAIN CIRCUIT BOARD 5 Play back the ALIGNMENT TAPE 6 Adjust the PG volume for ti...

Page 30: ...MENT TAPE COLOUR BAR SIGNAL 3 Connect the channel 1 scope probe to the S W PULSE TEST PIN of the PATH ADJ JIG 4 Connect the channel 2 scope probe to the ENVELOPE TEST PIN of the PATH ADJ JIG 5 Adjust the VR CONTROL of the PATH ADJ JIG for maximum envelope signal output of the alignment tape 6 Adjust the S T GUIDE ROLLER until the envelope signal waveforms of the entrance and exit sides are as show...

Page 31: ...onnect the channel 1 scope probe to the S W PULSE TEST PIN of the PATH ADJ JIG 4 Connect the channel 2 scope probe to the ENVELOPE TEST PIN of the PATH ADJ JIG 5 When turning the VR CONTROL of the PATH ADJ JIG clockwise or anti clockwise confirm that the envelope thickness changes uniformly 6 If the envelope is not uniform and regular adjust the S T GUIDE ROLLER 31 DRUM ENTRANCE DRUM EXIT Fine tun...

Page 32: ...the ENVELOPE TEST PIN of the PATH ADJ JIG 5 Adjust the VR CONTROL of the PATH ADJ JIG to the centre to obtain the maximum envelope signal of the ALIGNMENT TAPE 6 After operating the VCR in the REVIEW MODE about 15 secs change operation mode from REVIEW MODE to PLAY MODE and then make sure that the envelope waveform is restored to the maximum condition within 3 seconds 7 If the requirement is not s...

Page 33: ...cess DRUM ENTRANCE EXIT See page 31 X POSITION S W PULSE TEST PIN PATH ADJ JIG TEST POINTS ENVELOPE TEST PIN PATH ADJ JIG MEASURING EQUIPMENT OSCILLOSCOPE VR CONTROL PATH ADJ JIG ADJUSTMENT ADJUST BOSS MAIN BASE 1 Connect the PATH ADJ JIG to PTO1 of the MAIN CIRCUIT BOARD 2 Play back the ALIGNMENT TAPE COLOUR SIGNAL BAR 3 Connect the channel 1 scope probe to the S W PULSE TEST PIN of the PATH ADJ ...

Page 34: ...cp421vbl sch 1 Wed May 19 17 22 44 1999 VIDEO BLOCK DIAGRAM ...

Page 35: ...cp421abl sch 1 Wed May 19 17 19 52 1999 AUDIO BLOCK DIAGRAM ...

Page 36: ...cp421pbl1 sch 1 Wed May 19 17 21 31 1999 POWER BLOCK DIAGRAM ...

Page 37: ...PARTS LOCATION T V 10 26 15 14 19 23 18 2 3 5 9 11 1 12 24 4 25 37 6 17 8 20 7 22 13 16 21 NOTE The numbers on the exploded view below refer to the mechanical section of the Replacement Parts List ...

Page 38: ...SWITCHING IC I504 TC4053BP REGULATOR I505 KA7808 SWITCHING IC I506 TC4066BP AUDIO AMP I601 TDA1519B MAIN MICRO I701 SD545X0TP RESET I702 MN1280R MEMORY I703 AT24C08 10PC POWER SUPPLY I801 STR S5707 REGULATOR I802 KIA7812PI REGULATOR I804 KIA7812PI REGULATOR I805 KIA7806PI REGULATOR I806 KIA7806PI STANDBY I807 TOP210 REGULATOR I808 PQ12RF11 RGB DRIVE I901 TDA6106Q RGB DRIVE I902 TDA6106Q RGB DRIVE ...

Page 39: ...NSISTOR QC703 2SC1623 L6 T TRANSISTOR QC705 2SC1623 L6 T TRANSISTOR QC706 2SC1623 L6 T TRANSISTOR QCL06 2SC1623 L6 T TRANSISTOR QCN02 2SC1623 L6 T TRANSISTOR QCN03 2SC1623 L6 T TRANSISTOR QCY01 2SC1623 L6 T TRANSISTOR QCY02 2SA812 T2B TRANSISTOR QCY03 2SC1623 L6 T TRANSISTOR QCY05 2SA812 T2B TRANSISTOR QCY07 2SC1623 L6 T TRANSISTOR QCY08 2SC1623 L6 T TRANSISTOR QCY09 2SA812 T2B TRANSISTOR QCY10 2S...

Page 40: ...W 5 560 CARBON R573 RD AZ103J 0 17W 5 10K CARBON R576 RD AZ681J 0 17W 5 680 FUSIBLE R580 RF 2Y100J 0 5W 5 10 CARBON R585 RD AZ222J 0 7W 5 2 2K CARBON R601 RD 4Z221J 0 25W 5 220 CARBON R602 RD 4Z221J 0 25W 5 220 CARBON R603 RD AZ102J 0 17W 5 1K CARBON R701 RD 4Z100J 0 25W 5 10 CARBON R713 RD AZ101J 0 17W 5 100 CARBON R720 RD AZ101J 0 17W 5 100 CARBON R721 RD AZ101J 0 17W 5 100 CARBON R728 RD AZ472J...

Page 41: ...T102JCA 0 1W 5 1K S M CARB RC723 HRFT162JCA 0 1W 5 1 6K S M CARB RC724 HRFT162JCA 0 1W 5 1 6K S M CARB RC725 HRFT162JCA 0 1W 5 1 6K S M CARB RC729 HRFT473JCA 0 1W 5 47K S M CARB RC730 HRFT332JCA 0 1W 5 3 3K S M CARB RC732 HRFT103JCA 0 1W 5 10K S M CARB RC733 HRFT103JCA 0 1W 5 10K S M CARB RC736 HRFT272JCA 0 1W 5 2 7K S M CARB RC737 HRFT273JCA 0 1W 5 27K S M CARB RC740 HRFT103JCA 0 1W 5 10K S M CAR...

Page 42: ...5 1 2K S M CARB RCY55 HRFT103JCA 0 1W 5 10K S M CARB RCY56 HRFT512JCA 0 1W 5 5 1K S M CARB RCY57 HRFT103JCA 0 1W 5 10K S M CARB RCY59 HRFT470JCA 0 1W 5 47 S M CARB RCY60 HRFT271JCA 0 1W 5 270 S M CARB RCY61 HRFT271JCA 0 1W 5 270 S M CARB RCY70 HRFT104JCA 0 1W 5 100K S M CARB RCY71 HRFT104JCA 0 1W 5 100K S M CARB RCY72 HRFT103JCA 0 1W 5 10K S M CARB RCY74 HRFT154JCA 0 1W 5 150K S M CARB RCY75 HRFT1...

Page 43: ...CXF3A472Z 1kV S CERAMIC C807 CCZB1H102K 50V Q CERAMIC C808 CH1AFE472M 4kV S CERAMIC C810 CCXB3D681K 2kV S CERAMIC C813 CCXF1H103Z 50V Q ELECT C816 CEXF2A100V 100V ELECT C817 CEXF1E221C 25V ELECT C818 CEXF1E331V 25V ELECT C819 CEYN2G181P 400V ELECT C820 CEYF2C221V 160V ELECT C822 CEXF1C102C 16V ELECT C823 CEXF2G220V 400V ELECT C824 CEXF1H470V 50V ELECT C825 CEXF1C102V 16V ELECT C826 CEXF1E101C 25V ...

Page 44: ... Q S M CAP CC716 HCQK221JCA 50V S S M CAP CC717 HCBK333KCA 50V Q S M CAP CC720 HCBK104KCA 50V Q S M CAP CC721 HCBK104KCA 50V Q S M CAP CC725 HCBK103KCA 50V Q S M CAP CC727 HCBK103KCA 50V Q S M CAP CC728 HCBK103KCA 50V Q TANT CC729 HCTAH109MB 25V S M CAP CC730 HCQK471JCA 50V S S M CAP CC731 HCQK561JCA 50V S TANT CCL29 HCTBF100MB 16V S M CAP CCN01 HCBK104KCA 50V Q S M CAP CCN02 HCBK104KCA 50V Q S M ...

Page 45: ...71V 10V ELECT CN35 CEXF1C470A 16V ELECT CN36 CEXF1C100A 16V ELECT CN38 CEXF1E221V 25V ELECT CN46 CEXF1C101A 16V ELECT CN47 CEXF1C101A 16V CERAMIC CN51 CCZB1H101K 50V S CERAMIC CN53 CCZB1H101K 50V S CERAMIC CN54 CCZB1H101K 50V S CERAMIC CN55 CCZB1H101K 50V S ELECT CN56 CEXF1C470A 16V CERAMIC CN59 CDYF0H105K 5 5V ELECT CQ02 CEXF1H100V 50V ELECT CQ03 CEXF1E101V 25V CERAMIC CY07 CCZF1H103Z 50V Q MYLAR...

Page 46: ...S A51EAL15X17 C R T 17 4859625360 BACK COVER 18 4852154100 CABINET 19 4852072301 CRT PCB 20 TNP8EY001HH DEGAUSS COIL 21 58G0000074 MAIN PCB 22 TNP8EE001HH MODEL LABEL 23 485541581 PANASONIC BADGE 24 4855611928 POWER PCB 25 TNP8EP001HH SPEAKER 26 48A8306200 MISCELLANEOUS COMPONENTS CUSHIONS SET PTPKCPD201 OUTER CARTON M801 4858053700 CRT SOCKET SCT02 4859302930 TRANSISTORS TRANSISTOR T801 50M4042A2...

Page 47: ...38 6 2 EXPLODED VIEW OF DECK ASS Y BOTTOM VIEW 37 6 EXPLODED VIEW AND PA RTS LIST 6 1 EXPLODED VIEW OF DECK ASS Y TOP VIEW AC001 3 576 2 7 21 9 5 ...

Page 48: ...39 6 3 EXPLODED VIEW OF F L ASS Y 3 576 2 7 21 9 5 ...

Page 49: ...NUT HEX A1400 7391300211 LEVER RELAY A1500 97S2604100 GEAR CAM A1600 97S2701400 PINCH LEVER AS A1700 97SA310700 WASHER POLY A1800 97S3117300 L C BRKT TOT AS A1900 97SA310400 IDLER PLATE AS A2100 97SA311600 WASHER POLY A2200 97S3108200 TABLE REEL A2300 97S2901600 TABLE REEL A2350 97S2901600 POLY SLIDER A2400 97S3903600 TENSION BAND AS A2500 97SA310800 SPG TENSION A2600 97S3003500 S SUB BRAKE AS A27...

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Page 51: ...SCHEMATIC DIAGRAMS FOR MODELS ZEICHENERKLÄRUNG FÜR MODELL TX 21GV1C TX 14GV1C ...

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