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    Panasonic model TC-21PS70R color TV circuit diagram

    Hi !
    can anyone please give me the circuit diagram or service manual for this Panasonic 21 inch color TV model TC-21PS70R ?
    thanks !

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    Re: Panasonic model TC-21PS70R color TV circuit diagram

    this may help you?
    PANASONIC TC-21PS70R Service Manual
    wbr


    3 members found this post helpful.

    •   Alt5th August 2011, 09:47

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    Re: Panasonic model TC-21PS70R color TV circuit diagram

    @baraka42 Hi !
    thanks very much for the circuit diagram !!
    Its my home TV set and the power supply fuse keeps blowing.
    regards



    •   Alt6th August 2011, 06:43

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    Re: Panasonic model TC-21PS70R color TV circuit diagram

    If the fuse really blows absolutely instantly then this points to a short somewhere quite near the AC power input. The most common places would be:
    1. Transient voltage suppression = metal oxide varistor
    2. Degauss PTC
    3 Diodes in main bridge rectifier
    4 Main filter capacitor
    5. Power supply regulator (Power supply chopper transistor )

    In order to be able to eliminate these one by one need to do some small steps.
    First read the safety guidelines:
    Safety Guidelines for High Voltage and/or Line Powered Equipment
    0. Start by disconnect the main plug from the power lines
    1. Replace main fuse with a 230Vac/60W light bulb. (see picture #1)
    2. Disconnect jumpers JS801/JS802 (see picture #2)
    3. Reconnect main plug to the power lines
    4. Close main switch
    5. If light bulb will be permanently on, problems may be related to the MOV (see picture #3) or PTC (see picture #4)
    6. If light bulb shortly flash, then need to go one step ahead.
    7. Disconnect main plug from power lines
    8. Reconnect jumpers JS801/JS802
    9. Disconnect jumper JS826 (see picture #5)
    10. Reconnect power lines/ Close main switch
    11. Light bulb permanently ON, problems may be related to the bridge rectifier (see picture #6)
    12. Leave some time in between to discharge the main capacitor before start measuring in the circuit
    13. Other problems may be related to capacitors: C817/C807/C806/C809/C803 C824
    14. Light bulb pulse shortly ON and then OFF problems to the IC801 (see picture #10)
    15. Leave some time in between to discharge the main capacitor before start measuring in the circuit
    16. Measure resistance between pin 1 and pin 3 of the integrated circuit, low resistance = Replace IC801
    17. Check/Replace R809/R835
    18. Replace C811 (see picture #9)
    19. Need to test power supply. Disconnect tv set from power lines. Replace light bulb with standard fuse F801
    20. Disconnect Q551 collector from the circuit
    21. Reconnect the test light bulb 230Vac/60W from TPA12 to the GND.(+ capacitor C865)
    22. Reconnect tv to the power lines. Light bulb need to be permanently ON (medium light as not powered at nominal voltage).
    23. Test to obtain 140V on C865
    24. Disconnect tv from power lines
    25. Leave some time to discharge capacitors
    26. Test /replace Q551
    27. If Q551 OK, problems may be related to the high voltage transformer/horizontal deflection circuits/additional components related to
    28. Replace also capacitor C865 /68-100uF/160V


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    •   Alt6th August 2011, 08:25

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    Re: Panasonic model TC-21PS70R color TV circuit diagram

    @mister_rf
    Hi !
    thanks for taking the trouble to post a lengthy analysis
    Sure enough the power supply main bridge rectifier D802 was shorted so i replaced it and now the set is running fine
    A circuit diagram is very helpful in the sense that it gives you an overall picture of all components and wiring
    best regards !



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    Re: Panasonic model TC-21PS70R color TV circuit diagram

    @mister_rf
    @baraka42
    Hi !
    do you happen to know the service mode code for this Panasonic color tv?
    I would like to adjust the picture height and width etc
    thanks !
    regards
    Last edited by Tipu606; 29th August 2011 at 14:33.



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    Re: Panasonic model TC-21PS70R color TV circuit diagram

    The original chassis MX-5ZA. I have the following schematics:


    1 members found this post helpful.

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    Re: Panasonic model TC-21PS70R color TV circuit diagram

    @mister_rf
    thanks again for taking the trouble
    These files should be of great help to me
    best regards !!



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    Re: Panasonic model TC-21PS70R color TV circuit diagram

    @baraka42
    Hi !
    do you by any chance have the circuit diagram for the picture
    tube neck board?
    regards



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    Re: Panasonic model TC-21PS70R color TV circuit diagram

    Quote Originally Posted by Tipu606 View Post
    @mister_rf
    @baraka42
    Hi !
    do you happen to know the service mode code for this Panasonic color tv?
    I would like to adjust the picture height and width etc
    thanks !
    regards
    hai i am baburajan
    i will tell u a service mode . but dont know that it wil help u
    'first u set volume to zero then timer to "30" then press vol- & display button on remote at a same time



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