Another TNPA4782 Repair Thread

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  • ngen33r
    Member
    • Sep 2016
    • 24
    • United States
    #1

    Another TNPA4782 Repair Thread

    Well I acquired a free 50" and quickly found out via some blinking and probing that the SC board was shorted. I am working through the schematics starting with page 2 of 4 and testing every thing that I can.

    First thing I did was to unsolder most of the heat sinks and TO-220 components. The old Hakko 808 makes quick work of it. I still have 2 arrays to go. My initial findings are as follows:

    Shorted TO-220 Components List (Not Complete)
    Q401
    Q421
    Q422
    Q423
    Q601
    Q661

    Strangely all the diodes tested ok

    Shorted SMD Components (Thus Far)
    D618

    I have a list of components in circuit that have values that don't match and I have to find out why. I have removed a few of them and they measure GOOD but not in circuit. I will update this list as I progress but I need to do some forum searching to find out how to test the SMD transistors and IC's.

    More to come.
    Tags: None
    • John2gunsblaze
      New Member
      • Feb 2018
      • 3
      • United States of America
      #2
      Re: Another TNPA4782 Repair Thread

      I need a link to schematics

        Comment

        • tw2005
          Badcaps Legend
          • Oct 2011
          • 6458
          • Australia
          #3
          Re: Another TNPA4782 Repair Thread

          Originally posted by John2gunsblaze
          I need a link to schematics
          If you go to elektrotanya and search model, chances are you'll find a service manual with what you want

            Comment

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