Help Identifying Transformer on TV Power Board (GPX TD2420AB)

Discussion in 'Mobile Phones and Media Players' started by Monty Kensicle, Aug 9, 2016.

  1. Monty Kensicle
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    Monty Kensicle Yay!

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    Hello all. Not sure if this is the right place but I was hoping to get some advice.

    Recently my Father's TV (GPX TD2420AB) died mysteriously, he says one of our cats jumped up on the table where the TV lives and he heard a loud pop and it went dead. (Static discharge maybe?) After that it wouldn't turn back on.

    Upon opening it the power board had scorch marks and one of the capacitors in the center of the scorching had popped. I replaced all the through hole caps on the board but still no joy, but then I noticed a faint clicking noise coming from the large yellow transformer.

    IMG_20160809_181541507[1].jpg IMG_20160809_181549326[1].jpg IMG_20160809_181353004[1].jpg

    Attempting to get a reading with a multimeter from the transformer results in crazy fluctuating values and all DC power coming out of the board is only 2 volts or less.

    So fingers crossed all I should need to do is replace the transformer right? Well I can't seem to find any information on this transformer or the power board on the internet.

    I tried Googling the numbers printed on the transformer but nothing relevant comes up.

    What do you think I could replace it with?

    Thank you so much for your time.

    P.S. I found this. It appears to be the board in question, only the power socket and heatsinks differ. Depending on how much a new transformer is, would this be something I could swap successfully?
     
    Last edited by Monty Kensicle, Aug 9, 2016
  2. FAST6191

    FAST6191 Techromancer

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    The resistances of the primary and secondary windings are fluctuating?

    Your basic transformer is a pretty simple device so long as the power ratings and coil ratios match up (if you actually want to match input and output coil numbers then that is good but it is the ratio that matters) you should be OK as long as you are insulated where you need to be.

    Aliexpress board wise I would be careful -- I have seen some fairly radically different boards seem to come from the same PCB maker and screenprinting company.
     
  3. Monty Kensicle
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    Monty Kensicle Yay!

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    Yes that appears to be the case, the yellow transformer has 6 pins that lead to a cluster of capacitors which then go to a 9-pin connector that runs power to the TV. Trying to get a reading from said pins results in seemingly random numbers popping up and quickly being replaced with other values.

    Edit: I was testing it while it was live, probably not the best idea but after unplugging it and testing resistance between the pins on high side of the transformer I get "0.00".
     
    Last edited by Monty Kensicle, Aug 10, 2016
  4. FAST6191

    FAST6191 Techromancer

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    Is this in circuit? If the outputs are going to capacitors then feeding a voltage into it (what the resistance mode will do) or having a residual one from it being powered it going to do all sorts of fun things to readings.
     
  5. Monty Kensicle
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    Monty Kensicle Yay!

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    Everything has been done in-circuit thus far. I haven't had the time to set up my soldering iron to desolder the transformer.