Mitsubishi LT-52246 - Power Supply In Protection Mode

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  • Compgeke
    Badcaps Veteran
    • Feb 2014
    • 524
    • USA

    #1

    Mitsubishi LT-52246 - Power Supply In Protection Mode

    Good Evening guys,

    Last weekend we picked up a Mitsubishi LT-52246 for $3 in great condition - was worth the risk. When you first plug it in the power supply tries to start and then enters protection mode (you can hear the relay click - no front lights). If you unplug it the power supply tries to start again (and as such the front blue light turns on...until it fades off).

    Unplugging connector "PA" (the yellow one in the picture) keeps the power supply out of protection mode and the power light stays on fine. Unplugging everything from the board but with "PA" connected doesn't change anything.





    The power supply itself is surprisingly well built. The caps are Nichicon GU, PW and Rubycon ZL, Matsushita relays, etc. A bit of a surprise being as the plastics on this just feel cheap (despite being a TOTL model).



    What I'm suspecting might be the issue is these "T4/680A/UD" caps. The one closest to the centre looks a bit bulged at the vent but not the other sides.


    Anyways, does anyone else have any ideas what to check for on this? I haven't checked voltages yet as one of the tips of my multimeter probes got broke off making it quite hard to work with but as soon as I can get my hands on another I'll go into checking it out.
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  • budm
    Badcaps Legend
    • Feb 2010
    • 40746
    • USA

    #2
    Re: Mitsubishi LT-52246 - Power Supply In Protection Mode

    Those white connectors on the power supply board have labels next to them, so take the Voltage reading (when the TV is OFF and when the power switch is activated) of each pin and report the reading with each name of the pin.
    Never stop learning
    Basic LCD TV and Monitor troubleshooting guides.
    http://www.badcaps.net/forum/showthr...956#post305956

    Voltage Regulator (LDO) testing:
    http://www.badcaps.net/forum/showthr...999#post300999

    Inverter testing using old CFL:
    http://www.badcaps.net/forum/showthr...er+testing+cfl

    Tear down pictures : Hit the ">" Show Albums and stories" on the left side
    http://s807.photobucket.com/user/budm/library/

    TV Factory reset codes listing:
    http://www.badcaps.net/forum/showthread.php?t=24809

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