Vizio SV420M sometimes powers up with bad picture

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  • billansor
    Senior Member
    • Apr 2011
    • 85
    #1

    Vizio SV420M sometimes powers up with bad picture

    This Vizio SV420M came in with the complaint that it comes on sometimes but has bad picture. Customer could not describe if it was dim or partially scrambled.

    The set would not come on for us. We checked the 5 volt standby on the power supply board (1st picture) and is there. The 12 volt is not. The on off signal does work.

    All the caps, diodes, transistors were checked and do check okay. No burned marks or poor solder connections.

    Does anyone happen to have a schematic for this unit as there are two variable pots that are covered up.... See last picture and I have seen these change and I would like to see if this power board needs to have the voltages adjusted to the specific value..

    Thank you for your help

    Bill
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