Vizio XVT473SV mainboard question (w/ pics)

[Alderweis]

So during the first Patriot's game of the NFL season on sunday, about 5 minutes into the 2nd quarter, my TV lost its picture. Still saw back light, still had sound, but no picture. I powered it off, and waited a minute and powered it back on. Still no picture (no start logo, nothing) but definetely had back light, and sound.

I was able to change inputs, channels, etc. Sound on different inputs, but no signal at all. I've since let it sit for 3-4 hours unplugged, plugged it in, and powered it on with same behavior (sound, black light, no picture).

I took it apart, to see if there was anything amiss, and I found the attached pictures: a square black cap (?) with 220 marked on it, slightly off kilter.

Anybody know what this is? Can I remove it and replace it?

[Alderweis]

Re: Vizio XVT473SV mainboard question (w/ pics)

OK, so its possible that the mainboard came like that from the factory? Not sure. Continuity tests fine on it.

Meanwhile, I could not see the forest for the trees. I had previously inspected each cap and tested the continuity of the fuse on the tcon, but had missed that the entire damn thing was cooked!

New (refurb) tcon is on the way, hopefully resolving my issue. (First thing I'll do is rip the heatsink off and clean/reapply thermal paste.)

[ecking767]

Re: Vizio XVT473SV mainboard question (w/ pics)

Check the fuses on your T-CON board by making sure you have +12v on both ends of the fuse. or ohm the fuses out

If you have a magnifying glass examine the contacts and or ohm out your flat ribbon cable going to and from the T-CON and main-board. Then re-seating the flat ribbon cable on both ends (main-board and T-CON). post your results

[budm]

Re: Vizio XVT473SV mainboard question (w/ pics)

"I took it apart, to see if there was anything amiss, and I found the attached pictures: a square black cap (?) with 220 marked on it, slightly off kilter.

Anybody know what this is? Can I remove it and replace it?"
They are inductors for the Class D amplifier output filters.

[Alderweis]

Re: Vizio XVT473SV mainboard question (w/ pics)

Check the fuses on your T-CON board by making sure you have +12v on both ends of the fuse. or ohm the fuses out

If you have a magnifying glass examine the contacts and or ohm out your flat ribbon cable going to and from the T-CON and main-board. Then re-seating the flat ribbon cable on both ends (main-board and T-CON). post your results

Well, as that board is completely cooked, I'm going to be replacing the entire thing... so no need for further testing and thus no results

[Alderweis]

Re: Vizio XVT473SV mainboard question (w/ pics)

"I took it apart, to see if there was anything amiss, and I found the attached pictures: a square black cap (?) with 220 marked on it, slightly off kilter.

Anybody know what this is? Can I remove it and replace it?"
They are inductors for the Class D amplifier output filters.

OK. Should I worry about this (now that I know with certainty that it was the burned up tcon)? Is it possible it came from the factory cock-eyed? I can't really move it... so its not like its lose or anything.

[ecking767]

Re: Vizio XVT473SV mainboard question (w/ pics)

which board? How did you conclude your board is bad?

[Alderweis]

Re: Vizio XVT473SV mainboard question (w/ pics)

which board? How did you conclude your board is bad?

Check out the pictures I posted in the 2nd post. The tcon board is completely fried. I concluded this based on visual inspection of burned/melted wires.

[Agent24]

Re: Vizio XVT473SV mainboard question (w/ pics)

I see no burnt wiring.

[Alderweis]

Re: Vizio XVT473SV mainboard question (w/ pics)

Perhaps you are not expanding the pictures to the original size?

I'm including a detailed image.

Additionally, if you look at the image of the entire tcon I posted, you will see the white square outline around the heatsink/gpu area (could be misidentified as a shadow, but trust me.. it is absolutely not a shadow). On the right side of the image, the outline is white, turning to brown as you move left. Brown = burnt.

[ecking767]

Re: Vizio XVT473SV mainboard question (w/ pics)

That very unusual, that can't be a wire going underneath the BGA chip, can you clean that area with alcohol?

Its maybe a challenge finding this board in stock and very expensive board when you do.

[Alderweis]

Re: Vizio XVT473SV mainboard question (w/ pics)

That very unusual, that can't be a wire going underneath the BGA chip, can you clean that area with alcohol?

Its maybe a challenge finding this board in stock and very expensive board when you do.

The refurb replacement ($37 USD shipped) was shipped yesterday, should arrive the first of the week. I assure you it is a wire.

[Ijustwanttoseethepics]

Re: Vizio XVT473SV mainboard question (w/ pics)

Can you please post up black and white pics as well? Or mess with the sepia or something...

[Agent24]

Re: Vizio XVT473SV mainboard question (w/ pics)

Perhaps you are not expanding the pictures to the original size?

I'm including a detailed image.

Ah, I see it now. When you said wiring I thought you meant the flat flex ribbon cables etc.

From the flux residue I suspect that BGA has been reworked. That wire you say is burnt looks like a jumper wire someone has installed to repair a trace\pad under the BGA. The brown around the chip is just used flux that was not cleaned off.

It may even have come like that from the factory, possibly a manufacturing defect that was repaired.

Additionally, if you look at the image of the entire tcon I posted, you will see the white square outline around the heatsink/gpu area (could be misidentified as a shadow, but trust me.. it is absolutely not a shadow). On the right side of the image, the outline is white, turning to brown as you move left. Brown = burnt.

That chip *does* have a heatsink. That means it will get hot during normal operation. Some discolouration of circuit boards is to be expected around hot running parts. It may also just be more flux residue or discolouration from the BGA rework machine.

[Alderweis]

Re: Vizio XVT473SV mainboard question (w/ pics)

Ah, I see it now. When you said wiring I thought you meant the flat flex ribbon cables etc.

From the flux residue I suspect that BGA has been reworked. That wire you say is burnt looks like a jumper wire someone has installed to repair a trace\pad under the BGA. The brown around the chip is just used flux that was not cleaned off.

It may even have come like that from the factory, possibly a manufacturing defect that was repaired.



That chip *does* have a heatsink. That means it will get hot during normal operation. Some discolouration of circuit boards is to be expected around hot running parts. It may also just be more flux residue or discolouration from the BGA rework machine.

Well dang, that is crazy. Yeah, I'm the original owner so any rework would have been done prior to boxing. Crazy.

I did some additional scrubbing of the chip itself and that wire. I scrubbed pretty hard with a q-tip and alcohol and broke the little "jumper" wire off. Additionally, the ceramic chip die is coated with a waxy residue that came off when I scratched at it with my fingernail. If this was all from a rework, they sure left a mess. There is a ton of residue coating both the chip and the surrounding area.

I've included a picture of the wire/jumper/whatever after I cleaned it (before it came off... the white stuff is my q-tip cotton getting shredded). Also a before/after of the die surface, when I scrubbed it with a q-tip and some alcohol.

[Alderweis]

Re: Vizio XVT473SV mainboard question (w/ pics)

Well dang, that is crazy. Yeah, I'm the original owner so any rework would have been done prior to boxing. Crazy.

I did some additional scrubbing of the chip itself and that wire. I scrubbed pretty hard with a q-tip and alcohol and broke the little "jumper" wire off. Additionally, the ceramic chip die is coated with a waxy residue that came off when I scratched at it with my fingernail. If this was all from a rework, they sure left a mess. There is a ton of residue coating both the chip and the surrounding area.

I've included a picture of the wire/jumper/whatever after I cleaned it (before it came off... the white stuff is my q-tip cotton getting shredded). Also a before/after of the die surface, when I scrubbed it with a q-tip and some alcohol.

Additionally, I've been building PC's since mid-late 90's (The first CPU I cracked was my first 1ghz AMD T-bird, because of a badly installed heatsink ). My opinion of this is that the thermal paste used was of poor quality and very badly applied. They used too much, as is evidenced with the globs of it covering all sides of the chip on the die itself. This, coupled with the most likely below budget quality of the paste, over time caused the heating function of the heatsink and paste to degrade to the point of thermal failure.

[Alderweis]

Re: Vizio XVT473SV mainboard question (w/ pics)

OK, so the TCON got there yesterday and (aside from it being improperly shipped, in a too small box, with ZERO padding) it works!

So thanks for all for reading, sorry about misdirection with that off-kilter inductor (which I can now confidently assume came like that from the factory).

If you are like me and have no picture but DO have backlight and DO have sound and CAN switch inputs, there is a good chance it is your tcon. I got mine for $37 ebay refurb but it looks clean enough to be brand new.