Vizio XVT553SV Powers on and has sound but no picture

[1997eclipsegst]

Hey everyone,

I am working on a Vizio XVT553SV 55" LED tv and not sure what else to check.

When I received the set it would power on with backlight and sound but would not display any picture.

Voltages to the mainboard:
Fuse
F1-12.14 vdc
F3-5.07 vdc
F8-18.34 vdc

Tcon:
TF1-12.03 vdc
F4-5.12 vdc

After reading many posts about these and mainboard issues that they have I purchased a replacement mainboard from a "refurbished tv broke in transit" on ebay.

After swapping the mainboard out I have the exact same symptoms as above.

Does this possibly sound like a bad Tcon or panel? or another defective mainboard.

Any help would be great on anything else to check.

Thanks in advance,
Ryan

[MisterD]

Re: Vizio XVT553SV Powers on and has sound but no picture

I can't say for sure but it could be a bad T-Con board, I suggest checking all connectors/cables at the T-con board to ensure the ribbon cables are fully seated.

[1997eclipsegst]

Re: Vizio XVT553SV Powers on and has sound but no picture

Thanks for the reply MisterD.

I reseated the ribbons and connectors with no change.

I had the set on for a couple of hours (with no change to the picture) and noticed the large black heatsink was cool to the touch (room temperature) I would have assumed it would be a little warm?

The heatsink is held on with 4 spring loaded clips so I decided to take it off and have a peek underneath.

It appears that the gpu underneath is simmilar to a laptop gpu. I have had a few laptops that have had the gpu fail from the lead free solder joints breaking under the gpu.

I am thinking of trying a reflow (heatgun) and see if anything changes.

Any thoughts before I try?

[Moreno83]

Re: Vizio XVT553SV Powers on and has sound but no picture

Did you successfully reflowed a gpu from a laptop before? That chip looks alot like the Ati chips in laptops but i don't know if its soldered the same way.

[1997eclipsegst]

Re: Vizio XVT553SV Powers on and has sound but no picture

I have been able to get a couple laptops working with a reflow but have only lasted a couple moths before failing again. A full reball of the gpu is recommended.

But if this would at least show me that it would work I would know that everything else is good before ordering a replacement Tcon.

[MisterD]

Re: Vizio XVT553SV Powers on and has sound but no picture

Did you try the reflow?

[1997eclipsegst]

Re: Vizio XVT553SV Powers on and has sound but no picture

After looking at the T-con a little closer I noticed one side of the gpu was pulled up and the board was a little warped in that area. I decided to not even try a reflow and just ordered a replacement board.

I will update when the replacement board arrives.

[1997eclipsegst]

Re: Vizio XVT553SV Powers on and has sound but no picture

Wanted to update this.

I received the replacement T-con and the TV works perfect now.

Thanks for everyone's help.

[MisterD]

Re: Vizio XVT553SV Powers on and has sound but no picture

Good to hear you fixed it.

[ringking97]

Re: Vizio XVT553SV Powers on and has sound but no picture

thanks for the info but What is a T-CON board??

[budm]

Re: Vizio XVT553SV Powers on and has sound but no picture

thanks for the info but What is a T-CON board??

Timing Control board.

The board on the top middle of the LCD panel, it is connected between the LCD panel and the main board.