Vizio VS420LF1A, no sound, no backlight and no pic.

[dmesser100]

from what i can tell so far, im not getting 12volts from the power board when the tv is turned on. i get all other voltages, like 5v and the 2volt for the inverter on/off. here is the power board, its the kind that powers inverters all in one i think. can anyone point me in the right direction? thanks

[dmesser100]

Re: Vizio VS420LF1A, no sound, no backlight and no pic.

ok, if i leave it unpluged for a day or so. it will power up fine. Im pretty stumped, maybe a cold solder somewhere?

[tom66]

Re: Vizio VS420LF1A, no sound, no backlight and no pic.

When you do get it to power on, make sure to turn the sound up and select a working source. Wait for it to fail, do you get sound in the failed state?

[dmesser100]

Re: Vizio VS420LF1A, no sound, no backlight and no pic.

does get sound in faild state tom66, what does this mean?

[tom66]

Re: Vizio VS420LF1A, no sound, no backlight and no pic.

It means the main board is working fine but you are losing the backlight power. Therefore, concentrate any soldering work around the backlight transformers, their connections and the heatsink with the driver FETs on it. (this is the one near the two backlight transformers.)

[dmesser100]

Re: Vizio VS420LF1A, no sound, no backlight and no pic.

my sister says it still gets sound when the pic goes out. will check it for myself and get back out the solder iron if it does. thanks, will post back soon

[dmesser100]

Re: Vizio VS420LF1A, no sound, no backlight and no pic.

ok, it does not get backlight or data to the screen. and it does not get 12v from the power board. does get 2.5v on the ps on/off and 5v where its supposed to have output. how can i get the 5v and not the 12 from the board?