Trying to determine bad panel or t-con on Proscan TV

[ranergeo]

Heya! I've acquired a Proscan 42LED55SA tv that originally would turn off after about 2 minutes or less. Changing out the caps on the PCB solved that problem, but I was left with sound and a screen full of vertical red/green/grey-black lines (I've attached a picture attempting to show this, but still difficult to pic up with my camera!). I checked all the regulators on the t-con and the main board, and they all check out fine.

Since I saw lines on the screen, I decided to get another t-con supposedly out of a working set with a damaged screen, and I get 1/2 screen with a negative like image, and 1/2 screen full of grey and white banding. I've checked the ribbon connectors for proper seating with the picture staying the same each time.

The only "odd" thing I can find on any board is that one set of output voltages from my PCB to the Main is a 16VDC output putting out 17.2VDC (the 3.3, 5, and 24V outputs are all o.k.). Would this cause a problem, and how would I find the culprit on the board? If this wouldn't affect anything, could anyone offer a suggestion as to whether the problem is the t-con or panel (or something I've not thought of yet!!)? Thanks!!

[tom66]

Re: Trying to determine bad panel or t-con on Proscan TV

What is the voltage going to the T-con? Some T-cons use that voltage directly to drive the screen, if it is too high, it can cause problems. Personally I would suspect the T-con as it is rare for the whole panel to fail at once. It is possible, but rare.

[ranergeo]

Re: Trying to determine bad panel or t-con on Proscan TV

Thanks for the reply tom!

I have 11.82VDC at the fuse on the t-con, and 3.3V at the regulator. I had a hard time thinking it was the panel either, but with a supposedly new t-con, I figured it would clear up, unless it also was bad, or the wrong one for the tv (I got the same p/n, but some of the other board info was diffrent )

[MisterD]

Re: Trying to determine bad panel or t-con on Proscan TV

I saw a video on youtube where someone used cold spray/component cooler and sprayed it at the front edge of a lcd screen under the plastic bezel so it would get into the screen and if it corrected the lines in that area the screen was bad, I have never tried this and not sure about this method, but you may want to check into it or see if anyone has any advice about it.