Power supplies D8000 problems

Discussion in 'Hardware troubles and Repair support.' started by Jane, Jul 22, 2016.

  1. Jane

    Jane Member

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    I have two DM8000 power supplies( Panasonic ETXEZ654M7F versions).
    Both power supplies have 14V - pin 1, and I also connected 3,3V to pin 4( thanks Johnny for your great idea for testing ) but yet, no other voltages.
    I think the problem should be on the save side.
    I can NOT measure any voltages on IC 830 but I can measure the corect values on IC200( 10V, about 2V, one pin is ground)
    Can anyone give any idea how to try to repair them??
    Thanks
     
    Last edited: Jul 22, 2016
  2. Johnny B.

    Johnny B. Technical Support Staff Member Moderator

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    Seems to me a issue with one of the PC100-PC200 or PC300 3171 R 03 (Optocopler).
    See the datasheets on this topic.
    But to remove these, you need to remove the T200 transformer.
     
  3. Jane

    Jane Member

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    Johnny,
    Thank you for your prompt reply. I think PC100 is OK there is about 14V on both sides. But can you please let me know the voltages, I should measure, on PC200 and PC300?
     
  4. Johnny B.

    Johnny B. Technical Support Staff Member Moderator

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    The pc200/300 voltages are already noted on the drawing, as the pc200 one side 13.2v when in Off state, and 1.2v when in On state etc.
    But if you have the 14v om the pc100, and lower to the IC200 than it could be a resistor issue, maybe the 0 Ohm resistor R202 or others near the ic200.
    That is, if the 14v source is the pc100, but I think it is.
    Other possibility is a issue with the ic200.
     
  5. Jane

    Jane Member

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    Johnny, what do you mean by " lower to the IC200"?
    Do you mean that 10V is too small ?
    To be sure I measured again IC200 and it seems to be the same as you have in your drawings(13.2
    0 and 2.4V) . So it was my error during measuring previously.
    But IC 830 still has zero voltages.Do you know where the input voltage shloud come from?
    And what do you mean by OFF state? The state when there is no 3.3V on pin 4?
    Thank you for help
     
    Last edited: Jul 22, 2016
  6. Johnny B.

    Johnny B. Technical Support Staff Member Moderator

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    Okay, about the ic830 TL431 regulator.
    The cathode (10v), goes to the R302, after it it goes to one pin of the pc300.
    But what do you measure on the q200 on/off switch transistor.

    and Off state = when it's switched off.

    And as a references you can use the schematic from the 7020 psu.
    On this schematic is the ic830 the ic303.
    It's not fully useful, but may help to follow some parts.
     
  7. Jane

    Jane Member

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    Johnny,thank you for your reply.
    I measured
    Live side
    PC200 ON state: my value 0V your value 0V it means correct
    second pin
    PC200 ON state: my value 0V your value 0V it means correct

    PC300 Live side ON state: my value 0V your value 1V it means FAULT
    second pin
    PC300 Live side ON state: my value 0V your value 0V it means correct
    ------------------------------
    Save side:
    PC200 ON state: my value 1.5V your value 1.2V it means correct
    second pin
    PC200 ON state: my value 0V your value 0V it means correct

    PC300 ON state: my value 0V your value 12.1V it means FAULT
    second pin
    PC300 ON state: my value 0V your value 11V it means FAULT

    Further I measured in OFF state,live side
    PC200 my value 9.6V your value 14V - NOT correct but values on save side are correct from this Pc200

    Q200 - OFF state center pin 12.3V, if ON state 0V

    D101 ( live side) i measued in ON state there is only about 140V
    C100 ( live side) i measued in ON state only about 160V

    Do you have any further idea where the problem is?Thank you.
     
  8. Johnny B.

    Johnny B. Technical Support Staff Member Moderator

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    Today I had not the time to do some measurement, but tomorrow I have.
    In any case, at this moment I'm thinking of the PC300 or a issue on the hot side as the IC101 or Q100.
     
  9. Johnny B.

    Johnny B. Technical Support Staff Member Moderator

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    PC200 ON State..
    HOT Side (Collector) value 0V seems to be correct.
    HOT Side (Emiter (GND) value 0V is okay.
    Cold Side (Cathode) value 0V seems to be correct.
    Cold Side (Anode) value 1.5V seems to be fine.
    And so, the PC200 and Q200 seems to be working.
    OFF State,
    HOT Side (Collector) value 9.6V, normal value 14V looks to me not normal.
    Check the Q100 BC817 transistor, Check the ED100 diode hot side
    But check also the D300 diodes on the cold side if this leaks.


    PC300 ON State..
    HOT Side (Collector) value 0V normal 1V tells me that is didn't switched, but that could be normal because you have no voltage on the Cold side.
    HOT Side (Emiter (GND) value 0V is of course okay.

    D101 ( live side) i measured in ON state there is only about 140V
    C100 ( live side) i measured in ON state only about 160V
    Could have to do with the AC input voltages, mine where measured with a 220v input, you may have the 110v.

    Tip....
    For the working of the Optocouplers see youtube as Using Optocouplers with the Raspberry Pi.
    or how to test optocoupler.
     
  10. Jane

    Jane Member

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    Johnny, thank you for your reply.
    I checked

    D300 on save side. There is 0V( you have 12.1V)

    Q100 transistor on hot side.
    OFF STATE of Q100
    Base 9.7 (you have 14V), Emitor 9.7V( you have 14V)

    ON STATE of Q100
    Base 1.4V(I have not found yours), Emitor 2V( I have not found yours), collector 0.7V( you have 13V).
    As I can see Q100 transistor does not provide enough voltage for IC101 but voltage to base of Q100 is coming from PC200( optoisolator) and that optoisolator is controled ( if I understand in a correct way) from save side.
    ( quite complicated for me).
    Do you think q100 is faulty?
    Thank you for help
     
  11. Johnny B.

    Johnny B. Technical Support Staff Member Moderator

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    Q100 can be but does not happen that often.
    But given the measurement I think more of the IC101, which is often faulty.
     
  12. Jane

    Jane Member

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    Thank you for the reply. I bought Q100 and also IC101 and I will try to replace them and let you know
     
  13. Johnny B.

    Johnny B. Technical Support Staff Member Moderator

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    Yeah when the IC101 is faulty then the voltage from the Q100 will drops.
    Sometimes to zero, sometimes to a lower voltage which depend on how much is has become faulty.
    But be careful with the legs of the IC101, they are very thin and may break easily.
     
  14. Jane

    Jane Member

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    So today I have replaced IC101 and the power supply works great again.
    Johnny, thanks again for your help and advice.
     
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  15. Johnny B.

    Johnny B. Technical Support Staff Member Moderator

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    Ok, thanks for your message, and glad I could help with your problem.