Panasonic TX-21GV1 Service Manual
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Panasonic TX-21GV1 Service Manual

Panasonic TX-21GV1 Service Manual

Colour television video combination. z-421v chassis
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SPECIFICATIONS FOR TV
(All figures in brackets { } refer to TX-14GV1)
Power Source:
220-240V a.c., 50Hz
Power Consumption:
69W{54W}
Stand-by Power
Consumption:
3W
Aerial Impedance:
75Ω unbalanced, Coaxial Type
Receiving System:
PAL I, PAL-525/60
M.NTSC
NTSC (AV only)
Receiving Channels:
UHF E21-E69
Intermediate Frequency:
Video
38,9MHz
Audio
32,9MHz
Colour
34,47MHz
Video/Audio Terminals:
AV IN (Rear)
Video (21 pin) 1V p-p 75Ω
Audio (21 pin) 500mV rms 10kΩ
RGB (21 pin)
AV OUT (Rear)
Video (21 pin) 1V p-p 75Ω
Audio (21 pin) 500mV rms 1kΩ
AV Front
Audio (RCAx1) 500mV rms 10kΩ
Video (RCAx1) 1V p-p 75Ω
SPECIFICATIONS FOR VCR
GENERAL
temperature
format
tape width
tape speed
max. recording time with
full-size cassette
AUDIO
recording system
input
output
frequency range
signal to noise ratio
VIDEO
signal system
recording system
input
output
signal to noise ratio
horizontal resolution
High Voltage:
Picture Tube:
Audio Output Mono
(Music Power)
Headphones:
Accessories
supplied :
Dimensions:
Height:
Width:
Depth:
Net weight:
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.
5°C ~ 35°C (operating)
-20°C ~ 60°C (storage temperature)
standard
12.65mm
SP: 23.39mm/sec
LP: 11.70mm/sec
SP: 240min. with E-240 video cassette
LP: 480min. with E-240 video cassette
longitudinal track
-3.8dBm(500mVrms), more than 47kΩ, unbalanced.
-3.8dBm(500mVrms),less than 1kΩ, unbalanced
100Hz to 8KHz
40dB(more than)
PAL/SECAM colour and CCIR mono chrome signals,
625lines/50fields.
Rotary 4-head helical scan with a slant double azimuth
combination video head.
1Vp-p, 75Ω, unbalanced
1Vp-p, 75Ω, unbalanced
45dB with NETTETE IMAGE control at center position.
240 lines with NETTETE IMAGE control at center position
Colour Television
Video Combination
TX-21GV1
TX-14GV1
Z-421V Chassis
28kV ± 1,5kV
{25kV ± 1,5kV}
A51EAL155X17 (51cm)
{A34EAC01X (34cm)}
2 x 1,5W 8Ω Impedance
{2W
16Ω Impedance}
300Ω Impedance
3,5mm
Remote Control
2 x R6 (UM3) Batteries
Indoor Antenna {14" only}
532mm
{396,5mm}
514mm
{386mm}
485,2mm {367,5mm}
24kg
{13kg}
Panasonic CS ( U.K. ) Ltd.
ORDER No. SM-99066
WILLOUGHBY ROAD,
BRACKNELL,
BERKS.,
RG12 8FT.

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Summary of Contents for Panasonic TX-21GV1

  • Page 1 1Vp-p, 75Ω, unbalanced output 1Vp-p, 75Ω, unbalanced signal to noise ratio 45dB with NETTETE IMAGE control at center position. horizontal resolution 240 lines with NETTETE IMAGE control at center position Panasonic CS ( U.K. ) Ltd. WILLOUGHBY ROAD, BRACKNELL, BERKS., RG12 8FT.

  • Page 2: Table Of Contents

    CONTENTS SAFETY PRECAUTIONS................................2 SERVICE HINTS & DISASSEMBLY ............................3 ADJUSTMENT PROCEDURE..............................6 ALIGNMENT SETTINGS................................7 DESCRIPTION OF THE VCR MECHANISM ..........................8 BLOCK DIAGRAMS ................................34 PARTS LOCATION (TV) .................................37 REPLACEMENT PARTS LIST (TV) ............................38 PARTS LOCATION (VCR) ..............................47 REPLACEMENT PARTS LIST (VCR) .............................48 SAFETY PRECAUTIONS GENERAL GUIDE LINES It is advisable to insert an isolation transformer in the Reverse the a.c.

  • Page 3: Service Hints & Disassembly

    SERVICE HINTS How to remove the rear cover 1) Remove the screws as shown in Fig.2/Fig.3. TX-21GV1 TX-14GV1 Screw Screw Screw Screw Fig.3. Fig.2. DISASSEMBLY 1) Remove the 2 cable ties shown in Fig.4. 2) Remove the 7 connectors shown in Fig.5.
  • Page 4 DISASSEMBLY (Cont.) 3) Remove the 6 screws, three each side, from the top cover, as shown in Fig.6. 4) Remove the speaker connector as shown in Fig.6. 5) Remove earth strap shown in Fig.7. 6) Lift top cover and remove main pcb. Speaker Earth strap Connector...
  • Page 5 DISASSEMBLY (Cont.) Remove the 5 screws shown in Fig.10. Release the 5 chassis frame clips (shown in Fig.11.) and remove the main P.C.B. from the chassis frame. Screws Screws Fig.10. Clips Clips Fig.11.

  • Page 6: Adjustment Procedure

    ADJUSTMENT PROCEDURE Item / Preparation Adjustments Sub Tuner AFT Adjust L201 (AFT COIL) for 2,2V ± 0,1V. 1) Set a signal generator with -RF FREQUENCY = 38,9MHz -RF OUTPUT LEVEL = 80±5dBuV. 2) Connect a signal generator RF output to TP2 (TUNER IF OUTPUT).

  • Page 7: Alignment Settings

    ALIGNMENT SETTINGS: (The figures below are nominal and used for representative purposes only.) 1) Place the TV in Programme position 70, set the Sharpness to minimum position, press the down button (- / v) on the customer controls at the front of the TV and at the same time press the VCR INDEX button on the remote control, this will place the TV into the Service Mode.

  • Page 8: Description Of The Vcr Mechanism

    DESCRIPTION OF THE VCR MECHANISM Characteristic of the K-Deck mechanism _ K-Mecha Deck follows the VHS standard and uses three motors (DRUM MOTOR, CAPSTAN MOTOR and L/C MOTOR). The L/C MOTOR is used to drive FRONT LOADING. _ The deck recognises each mode by using a 4-BIT MODE signal. This 4-BIT MODE signal is generated by the CAM SWITCH, which is driven by the L/C MOTOR.
  • Page 9 ASSEMBLY DIAGRAM AND MAJOR PARTS CHECK BOTTOM VIEW Fig.13. 1) CAPSTAN MOTOR 5) REEL GEAR TOTAL ASSEMBLY 9) DRUM TOTAL ASSEMBLY 2) F/L RACK 6) RECORD SAFETY LEVER LOADING RACK ASSEMBLY 3) CONNECT PLATE 7) L LOADING ASSEMBLY 4) REEL BELT 8) R LOADING ASSEMBLY...
  • Page 10 DISASSEMBLY AND REPLACEMENT 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. A0400 Front loading assembly separation Fig.14.
  • Page 11 DISASSEMBLY OF THE VCR 1) Remove the screw holding the F/L BRACKET R and move the F/L BRACKET R in the direction of the arrow to separate it from the TOP PLATE and CASSETTE HOLDER ASSEMBLY. 2) Remove the CASSETTE HOLDER ASSEMBLY. Disassembly of the front loading assembly Fig.15.
  • Page 12 DISASSEMBLY OF THE VCR (Cont.) 4) Remove the screw holding the PRISM LINK L. 5) Release the hook B by pushing it in the direction of the arrow and remove the DOOR OPENER. Disassembly of the top plate Fig.17. 6) Remove the LOADING LEVER ASSEMBLY by pressing the connected section of the LOADING LEVER ASSEMBLY in the direction of the arrows.
  • Page 13 DISASSEMBLY OF THE VCR (Cont.) NOTE Reassemble the FRONT LOADING MECHANISM in the reverse order. Confirm that the two bosses on the left side of the CASSETTE HOLDER are inserted into the groove on the left s ide of the top plate. Insert the two bosses on the right side of the cassette holder into the groove of the FRONT LOADING BRACKET R.(Fig.19).
  • Page 14 REEL BELT, LOADING RACK ASSEMBLY, S/T SLANT POLE ASSEMBLY REMOVAL 1) Turnover the DECK MECHANISM and remove the REEL BELT (1). 2) Remove one POLY WASHER (2). 3) Remove the LOADING RACK ASSEMBLY (3). 4) Remove R and L LOADING ASSEMBLIES (4&5). 5) Remove the S and T SLANT POLES (6&7) by pulling them in the direction of the arrows.(Fig.21) CAUTION...
  • Page 15 A/C HEAD ASSEMBLY REMOVAL 1) Remove the hex nut (1) from the A/C HEAD POST (4) of the MAINBASE.(Fig.23) 2) Remove the A/C HEAD ASSEMBLY (2) from the MAINBASE. 3) Remove the A/C HEAD SPRING (3) from the A/C HEAD ASSEMBLY. NOTE After reassembling, adjust the TAPE TRANSPORTING SYSTEM, referring to ADJUSTMENT OF THE TAPE TRANSPORTING SYSTEM.
  • Page 16 CAM GEAR, RELAY LEVER AND F/L RACK REMOVAL (Cont.) CAM GEAR DATUM HOLE OF CAM GEAR DATUM HOLE OF MAINBASE F/L RACK Assembly of the cam gear and front loading rack Fig.26. Assembly of the cam gear and relay lever Fig.25.
  • Page 17 TENSION BAND ASSEMBLY REMOVAL 1) Remove the TENSION SPRING (2) from the MAINBASE (1). 2) Turn the DECK MECHANISM over. 3) After separating the tab of hook "A", remove the TENSION BAND ASSEMBLY (3). NOTE After assembling the TENSION BAND ASSEMBLY on the MAINBASE, adjust the position of the TENSION POLE as shown in fig.30.
  • Page 18 CAPSTAN MOTOR REMOVAL 1) Remove the 3 screws fixing the CAPSTAN MOTOR and separate the CAPSTAN MOTOR. Capstan motor removal Fig.31. IDLER PLATE TOTAL ASSEMBLY & S/T REEL TABLE REMOVAL 1) Remove one POLY WASHER (1) from the REEL GEAR POST (2) and remove the IDLER PLATE TOTAL ASSEMBLY (3) from the MAIN BASE.
  • Page 19 FE HEAD REMOVAL 1) Remove the screw (1) fixing the FE HEAD (2) and remove the FE HEAD from the MAINBASE. Fe head removal Fig.33. REEL GEAR TOTAL ASSEMBLY & CONNECT PLATE REMOVAL 1) Turn over the DECK MECHANISM and remove the POLY WASHER (1) from the REEL GEAR POST (2). 2) After separating tab "B"...
  • Page 20 MECHANICAL ADJUSTMENT When operational problems occur or the mechanism is reassembled, be sure to confirm the following instructions. 1) Make sure that the DATUM HOLE of the CAM GEAR is aligned with the DATUM HOLE in the MAINBASE in the EJECT mode, as shown in fig.35.
  • Page 21 MECHANICAL ADJUSTMENT (Cont.) 3) When reassembling the L/C BRACKET TOTAL ASSEMBLY on the MAINBASE, make sure that the two triangular marks of the CAM SWITCH are aligned with each other as shown in fig.37. TRIANLE MARKS MUST MEET EACH OTHER Datum position of cam switch triangular marks Fig.37.
  • Page 22 MECHANICAL ADJUSTMENT (Cont.) 5) Ensure that the triangular mark "A" on the L LOADING ASSEMBLY is aligned with the notch "B" on the R LOADING ASSEMBLY, as shown in fig.39. 6) Ensure that the teeth of the LOADING RACK ASSEMBLY are aligned with 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.
  • Page 23 BACK TENSION MEASUREMENT 1) Confirm the position of the TENSION POLE is correct. Refer to "TENSION POLE POSITION ADJUSTMENT" 2) Play back a T-120 TAPE at its centre position without assembling F/L ASSEMBLY and wait until the TAPE run is stabilised (about 5-10 secs).
  • Page 24 MECHANICAL MODE (OPERATING THE VCR WITHOUT A CASSETTE TAPE) 1) Remove the FRONT LOADING MECHANISM from the DECK MECHANISM. 2) Pull the F/L RACK. 3) The S/T POLE BASES are loaded and PLAY BACK MODE starts. 4) Turn off the power when the MECHANISM is in the desired position. TENSION POLE POSITION ADJUSTMENT 1) Change MECHANICAL MODE to PLAY MODE.
  • Page 25 ADJUSTMENT OF TAPE TRANSPORTING SYSTEM Generally the TAPE TRANSPORTING SYSTEM has been precisely adjusted in the factory and does not ordinarily require readjustment, but when noise and tape damage take place and part assemblies that comprise the TAPE TRANSPORTING SYSTEM are replaced, check and readjust the TAPE TRANSPORTING SYSTEM. Refer to the following flow chart in order to adjust the TAPE TRANSPORTING SYSTEM.
  • Page 26 ADJUSTMENT OF TAPE TRANSPORTING SYSTEM (Cont.) The schematic diagram of tape transporting system Fig.42. When the parts as shown in fig.42 are replaced, the TAPE TRANSPORTING SYSTEM has changed. To prevent this, it is essential to observe the following instructions. ADJUSTMENT OF THE S/T GUIDE ROLLER 1) Play back a T-120 TAPE.
  • Page 27 ADJUSTMENT OF THE AUDIO AZIMUTH 1) Play back the ALIGNMENT CASSETTE TAPE (NTSC:DN2 (SP 7KHz), PAL: DP2 (SP 6KHz)) 2) Observe audio signals on an OSCILLOSCOPE. 3) Turn the A/C HEAD AZIMUTH SCREW to obtain the maximum audio output signal (-9 ~-3dBm) Fig.44. Audio control head assembly Fig.44.
  • Page 28 X-POSITION ADJUSTMENT 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 adjustment fixture to PTO1 of the MAIN CIRCUIT BOARD. 2) Play back the ALIGNMENT TAPE (COLOUR BAR ALIGNMENT).
  • Page 29 PLAYBACK PHASE ADJUSTMENT S/W PULSE TEST PIN PATH ADJ. JIG TEST POINTS VIDEO OUT MAIN CIRCUIT BOARD MEASURING EQUIPMENT OSCILLOSCOPE ADJUSTMENT VR595 (PG SHIFTER) MAIN CIRCUIT BOARD The Phase generator (PG) shifter decides the VIDEO HEAD switching point when a TAPE is played back. In case the Phase generator (PG) shifter is not correctly tuned, HEAD switching noise or vertical jitter may occur.
  • Page 30 LINEARITY ADJUSTMENT 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 S/T GUIDE ROLLER TAPE TRANSPORTING SYSTEM 1) Connect the PATH ADJ. JIG to PTO1 of the MAIN CIRCUIT BOARD. 2) Play back the ALIGNMENT TAPE (COLOUR BAR SIGNAL).
  • Page 31 DRUM ENTRANCE / EXIT 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 S/T GUIDE ROLLER TAPE TRANSPORTING SYSTEM 1) Connect the PATH ADJ. JIG to PTO1 on the MAIN CIRCUIT BOARD. 2) Play back the ALIGNMENT TAPE (COLOUR BAR SIGNAL).
  • Page 32 REVIEW / PLAY 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 S/T GUIDE ROLLER TAPE TRANSPORTING SYSTEM 1) Connect the PATH ADJ. JIG to PTO1 of the MAIN CIRCUIT BOARD. 2) Play back the ALIGNMENT TAPE (SP COLOUR BAR SIGNAL).
  • Page 33 AUDIO OUTPUT (A/C HEAD TILT & HEIGHT ADJUSTMENT) TEST POINTS AUDIO OUTPUT AUDIO OUTPUT JACK MEASURING EQUIPMENT OSCILLOSCOPE 1) Connect the OSCILLOSCOPE to the AUDIO OUTPUT JACK. 2) Play back the ALIGNMENT TAPE (NTSC DN1 (SP 1KHz), PAL DP1 (SP 1KHz)). 3) Check the AUDIO OUTPUT SIGNAL is -9~-3dBm.

  • Page 34: Block Diagrams

    VIDEO BLOCK DIAGRAM -1 - Wed May 19 17:22:44 1999...
  • Page 35 AUDIO BLOCK DIAGRAM ch-1 - Wed May 19 17:19:52 1999...
  • Page 36 POWER BLOCK DIAGRAM cp421pbl1.sch-1 - Wed May 19 17:21:31 1999...

  • Page 37: Parts Location (Tv)

    PARTS LOCATION T.V. NOTE: The numbers on the exploded view below refer to the mechanical section of the Replacement Parts List.

  • Page 38: Replacement Parts List (Tv)

    REPLACEMENT PARTS LIST Important Safety Notice Components Identified by mark have special characteristics important for safety. * When replacing any of these components, use only manufacturers specified parts. In case of ordering these spare parts, please always add the complete Model-Type number to your order.
  • Page 39 Cct Ref Parts Number Description Cct Ref Parts Number Description D804 D1S1888 DIODE QC701 2SC1623-L6/T TRANSISTOR D807 DRGP15J DIODE QC703 2SC1623-L6/T TRANSISTOR D808 DRGP15J DIODE QC705 2SC1623-L6/T TRANSISTOR D809 DRGP15J DIODE QC706 2SC1623-L6/T TRANSISTOR D810 DRGP15J DIODE QCL06 2SC1623-L6/T TRANSISTOR D811 DRGP30J DIODE...
  • Page 40 Cct Ref Parts Number Description Cct Ref Parts Number Description R565 RD-AZ561J CARBON 0.17W FILTERS R573 RD-AZ103J CARBON 0.17W L801 5PLF24A1 LINE FILER R576 RD-AZ681J CARBON 0.17W SF01 5PJ1952M SAW FILTR R580 RF-2Y100J FUSIBLE 0.5W SF03 5PJ1952M SAW FILTR R585 RD-AZ222J CARBON 0.7W...
  • Page 41 Cct Ref Parts Number Description Cct Ref Parts Number Description RC511 HRFT301JCA S.M.CARB 0.1W RC730 HRFT332JCA S.M.CARB 0.1W 3.3K RC512 HRFT680JCA S.M.CARB 0.1W RC732 HRFT103JCA S.M.CARB 0.1W RC513 HRFT301JCA S.M.CARB 0.1W RC733 HRFT103JCA S.M.CARB 0.1W RC514 HRFT750JCA S.M.CARB 0.1W RC736 HRFT272JCA S.M.CARB 0.1W...
  • Page 42 Cct Ref Parts Number Description Cct Ref Parts Number Description RCN32 HRFT182JCA S.M.CARB 0.1W 1.8K RCY70 HRFT104JCA S.M.CARB 0.1W 100K RCN34 HRFT333JCA S.M.CARB 0.1W RCY71 HRFT104JCA S.M.CARB 0.1W 100K RCN40 HRFT104JCA S.M.CARB 0.1W 100K RCY72 HRFT103JCA S.M.CARB 0.1W RCN41 HRFT106JCA S.M.CARB 0.1W RCY74...
  • Page 43 Cct Ref Parts Number Description Cct Ref Parts Number Description C810 CCXB3D681K CERAMIC CAPACITORS S) C813 CCXF1H103Z CERAMIC Q) C107 CEXF1H100V ELECT —) C816 CEXF2A100V ELECT 100V —) C120 CEXD1H109F ELECT —) C817 CEXF1E221C ELECT —) C225 CEXF1H220V ELECT —) C818 CEXF1E331V ELECT...
  • Page 44 Cct Ref Parts Number Description Cct Ref Parts Number Description CC512 HCBK103KCA S.M.CAP Q) CC725 HCBK103KCA S.M.CAP Q) CC513 HCBK104KCA S.M.CAP CC727 HCBK103KCA S.M.CAP Q) Q) CC517 HCBK102KCA S.M.CAP CC728 HCBK103KCA S.M.CAP Q) CC518 HCBK102KCA S.M.CAP CC729 HCTAH109MB TANT —) CC520 HCBK102KCA S.M.CAP...
  • Page 45 CN36 CEXF1C100A ELECT —) TNP8EE001LL MAIN PCB CN38 CEXF1E221V ELECT —) 485541584- MODEL LABEL CN46 CEXF1C101A ELECT —) 4855611927 PANASONIC BADGE CN47 CEXF1C101A ELECT —) TNP8EP001LL POWER PCB CN51 CCZB1H101K CERAMIC S) 48A830610 SPEAKER CN53 CCZB1H101K CERAMIC S) MISCELLANEOUS COMPONENTS...
  • Page 46 CCXB1H471K CERAMIC S) C914 CZSL1H180J CERAMIC S) C915 CZSL1H180J CERAMIC S) C916 CZSL1H180J CERAMIC S) DIFFERENCES FOR MODEL TX-21GV1 MECHANICAL PARTS 4859625360 A51EAL15X17 C.R.T. 4852154100 BACK COVER 4852072301 CABINET TNP8EY001HH CRT PCB 58G0000074 DEGAUSS COIL TNP8EE001HH MAIN PCB 485541581- MODEL LABEL...

  • Page 47: Parts Location (Vcr)

    3$576 /2&$7,21 9&5 6. EXPLODED VIEW AND PA RTS LIST 6-2. EXPLODED VIEW OF DECK ASS’Y (BOTTOM VIEW) 6-1. EXPLODED VIEW OF DECK ASS’Y (TOP VIEW) AC001...
  • Page 48 3$576 /2&$7,21 9&5 6-3. EXPLODED VIEW OF F/L ASS’Y...

  • Page 49: Replacement Parts List (Vcr)

    REPLACEMENT PARTS LIST Important Safety Notice Components Identified by mark have special characteristics important for safety. * When replacing any of these components, use only manufacturers specified parts. In case of ordering these spare parts, please always add the complete Model-Type number to your order.
  • Page 51 SCHEMATIC DIAGRAMS FOR MODELS ZEICHENERKLÄRUNG FÜR MODELL TX-21GV1C / TX-14GV1C...

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