Toshiba 40XV640u strange screen issue; need help diagnosing...

[vagabondjjm]

As the pictures show, I'm getting vertical and horizontal lines. The lines fade if nothing is being displayed on the screen and also show over the on screen menu.

When I have a source on, such as my 360, the lines show over everything, but strangely enough, it almost looks like the color of thing "underneath" the lines is still right.

I've changed the t-con out and I'm getting the exact same results.

I've also checked the tabs on the lcd itself and they seem to be fine. They are unaffected by any slight pressure anywhere (I used a dense foam, not my hand).

I'm mystified on this one. Could the main/video board cause something like this to occur? I don't see any obvious indicators like bulged caps or blown fuses anywhere, but going from the tcon backwards, this is the next thing in line.

Also, same thing happen on any input, even if there isn't a source on.

Thanks all for any insight you may have!

[selldoor]

Re: Toshiba 40XV640u strange screen issue; need help diagnosing...

May well be a bad panel
Did you clean the lvds cables when you had them off?
Was the TCON an EXACT replacement, if used, off the same size panel.
If you can get into the service menu try a factory reset.

[MisterD]

Re: Toshiba 40XV640u strange screen issue; need help diagnosing...

I had a Similar situation vertical lines like what you have, where pressing on the tab bonds did not do anything, I then used a hair dryer to heat up the tab bonds and then things started changing the lines went away and I had a normal picture, then after that I was able to get a response when pressing on the bad tab bonds.

[cashkennedy]

Re: Toshiba 40XV640u strange screen issue; need help diagnosing...

I had a 40" sony that had a tab issue, that did not respond to pressure on the tabs, and would blur / some items on the screen kinda like it was stretching them out up and down. Like when the sony logo shows on the screen it would read sony fine in the middle, but the sony had a streak / shadow going up and down in bright pink...

I finally was able to fix that set using the resistor trick / which is documented on this forum. If you completly disasemble the set you can fairly easily try the resistor trick, but the hard part is permanently soldering the resistor to a plastic tab...

https://www.badcaps.net/forum/showth...40s5100&page=2 I linked videos in this topic about the resistor tab fix.

https://www.badcaps.net/forum/showth...ht=kdl-40s5100 shows pictures of the symptoms it had.

[vagabondjjm]

Re: Toshiba 40XV640u strange screen issue; need help diagnosing...

Thanks all for your replies! I am trying each in order this evening, starting with a factory reset if I can do it. Interested to see what heat does to the tabs. Any advice on heat settings and time for each tab?

[vagabondjjm]

Re: Toshiba 40XV640u strange screen issue; need help diagnosing...

Okay well I tried about everything to no avail. Took a look at the back of the video board and it looks pretty bad on one part of the underside, but you wouldn't know from looking at the top.

Considering the variables at this point I think I'm just going to sell the boards I know are good and move on. Time is money too . Thanks everyone for taking the time to try and help!