Vizio VT470M goes black after couple of minutes (no picture, yes sound)

[Romanmtz]

So last year I bought this TV on craigslist for $100 with the same exact problem with the intention of repairing it. I would turn the TV on, the Vizio logo would appear, the TV would work normally for a couple of minutes and the POOF, screen would go blank but the sound would still work.

So doing some research I figured it was either the T-Con or the main board that was at fault. Being the cheaper part, I replaced the T-con board first and nothing. After that I bought a new main board (CBPF9D1KZ6) and voila! That repaired it and it worked happily ever after...

Until last week... same thing started happening. I was playing on my PS3 and poof... just went out, sound still working and turning off and on gave me the same result as when I first got the TV. I really don't want to have to buy another main board... especially now that they are less available and more expensive.

So can I do anything to the main board to repair it? Is it a heat issue?

Any help would be appreciated. Thanks!

[bbushong]

Re: Vizio VT470M goes black after couple of minutes (no picture, yes sound)

By 'going black' do you mean the backlights turn off, or the picture goes away and the backlights are still on?

I'm not much on troubleshooting flat panel sets, but I've got the same model that will work for hours when I initially turn it on (after being off for about 30 minutes), but when I turn it off, then back on, I get no display except for backlights. I'm going to replace the capacitors on the main board (pretty much isolated it to that board, and there are a few in the power switching circuit that I can see), and see what happens. I got the TV from a neighbor that was throwing it away, so it's no great loss if the caps don't work. They were about $20 for all of them (plus spares). I wanted to avoid buying any expensive boards that may fail again in the future, with me not having a clue what's going wrong with them...

[Romanmtz]

Re: Vizio VT470M goes black after couple of minutes (no picture, yes sound)

Yeah, I get backlights but no image. Could it be just a matter of replacing caps? Are you just going to try replacing them all or are there a certain number of known problematic ones? Thanks!

Roman

[Romanmtz]

Re: Vizio VT470M goes black after couple of minutes (no picture, yes sound)

Bump...

[budm]

Re: Vizio VT470M goes black after couple of minutes (no picture, yes sound)

Check the fuse on the T-CON board or check and see if you do have 12V at both ends of the fuse with ref. to the chassis ground.

[pajodha]

Re: Vizio VT470M goes black after couple of minutes (no picture, yes sound)

I need some help on my board

[pajodha]

Re: Vizio VT470M goes black after couple of minutes (no picture, yes sound)

vizo va370ma the main board the 4 volts regulator I need some help on that

[budm]

Re: Vizio VT470M goes black after couple of minutes (no picture, yes sound)

vizo va370ma the main board the 4 volts regulator I need some help on that

You should start a new thread since your TV is not the same model.

[MartyMcCall]

Re: Vizio VT470M goes black after couple of minutes (no picture, yes sound)

budm, I didn't see any images for the vt470m tear down within the link you provided. Is there another model that is comparable to it that I can look at?

The issue with my tv is the back light is on but no picture or sound.

This unit has been sitting in a corner for almost 2 years now. At first I thought it was a bad power supply and I was just going to replace that. But tonight I actually plugged it in and low and behold a picture and sound showed up. Only lasted for maybe 4 minutes. Then the screen went black and the was a solid beep tone coming from it.
Now it's just sitting here with no image and the back light lit.