Vizio VS42L LCD displaying only black and white

[Cosmo66]

Does anyone know what could cause this condition? I'm thinking of picking up this TV, but I'm haggling with the guy a little. He says the picture just lost color and is suddenly grey and white. I was wondering if anyone has ever had this problem before? A google search didn't really yield any useful information, and I'd like to have a general idea of what I'm getting into before make a decision

Is this a most likely a TCON failure?

Any help would be appreciated, thanks!

[tom66]

Re: Vizio VS42L LCD displaying only black and white

If he's using analog cable that could be a fault with the colour-burst decoding.
If the menu's OK, it's the main for sure, otherwise it could be main or t-con.

[Cosmo66]

Re: Vizio VS42L LCD displaying only black and white

On the main, do you think would most likely be a faulty chip?

[tom66]

Re: Vizio VS42L LCD displaying only black and white

I have no idea. Either way, tracing the problem would mean oscilloscope and careful signal analysis. Easier to replace the board.

[Cosmo66]

Re: Vizio VS42L LCD displaying only black and white

So, most likely I'll be changing either the TCON, or the main board,

unless the guy's wife or kids messed up the color settings on the menu and he has no idea

He won't take anything less than $75. Normally I'd pass, I refuse to spend more than $50 for a not working tv, but I have another Vizio that's almost identical. It would be nice to be able to swap boards back and forth.

[tom66]

Re: Vizio VS42L LCD displaying only black and white

I'd normally pay no more than £50/$80US for a faulty 42", I usually pay around £40, that is a good price you have there.

[Cosmo66]

Re: Vizio VS42L LCD displaying only black and white

I picked up the TV. Here is what the picture looks like.

[johnboy1313]

Re: Vizio VS42L LCD displaying only black and white

I'm going public and putting my money on T-Con.

[Cosmo66]

Re: Vizio VS42L LCD displaying only black and white

I have another Vizio, the exact same model, with a ribbon cable issue. Tomorrow I'll swap out the boards and find the culprit.

I also have the luxury of being able to use the good board as a reference to try and troubleshoot down to component level. Should be a hoot!

[tom66]

Re: Vizio VS42L LCD displaying only black and white

It looks like t-con to me. Menus good/bad? On HDMI is good/bad?

[Cosmo66]

Re: Vizio VS42L LCD displaying only black and white

I replaced the tcon. Problem solved. I'm gonna try to troubleshoot the board down to the component. Wish me luck. . .

[tom66]

Re: Vizio VS42L LCD displaying only black and white

My bet would be it's in the large IC. Good luck with that...

[Cosmo66]

Re: Vizio VS42L LCD displaying only black and white

By the way, thank you tom66. I was gonna pass on this until you made me realize $75 wasn't bad. Good call

[Cosmo66]

Re: Vizio VS42L LCD displaying only black and white

My bet would be it's in the large IC. Good luck with that...

I think you may be correct. I checked every component I could put a probe to, using the good board I have as reference, and couldn't find a single problem. The large IC gets very hot with the TV on.

There's really not much else to fail on that board. Maybe I'll drown the thing in flux and take a heat gun to it as a final measure. It's a BGA chip with at least 100 pins, I wouldn't be shocked if at least one of those pins is open.

[Dgtech]

Re: Vizio VS42L LCD displaying only black and white

If the large chip got hot to the touch, most likely it's damaged. Not really worth your time in trying to fix it.