TCL 40FS3800 Stuck in Screen Test Pattern

[Louis82]

Hello there,

I have a TCL Tv that the initial problem was that it would play fine for 10 to 15 seconds and it would cut off. So I replaced the main board and tv played great but when I was closing the tv I noticed a distorted picture. I wiggle the LVDS cable that connects main board to interface board (not sure if I would call it T-Con) and picture looked good. I taped the LVDS cable thinking it was loose but nothing, problem still come and goes when I wiggle cable.
I decided to reversed the cable (it works with samsung tvs) and tv now shows like if its stuck in a test pattern. It shows green, blue, red color (see pictures).
I couldn't understand why so I put it back to like it was originally and now it doesnt show anything at all, just the backlight appears to be on and sound.

Any suggestions? I added a few pictures.

Thanks for your time.

[dskall]

Re: TCL 40FS3800 Stuck in Screen Test Pattern

Check fuse on panel pcb

[Louis82]

Re: TCL 40FS3800 Stuck in Screen Test Pattern

Fuse is good

[budm]

Re: TCL 40FS3800 Stuck in Screen Test Pattern

I would remove the cable and inspect the exposed conductors at both ends to make sure they are not damaged.

[Louis82]

Re: TCL 40FS3800 Stuck in Screen Test Pattern

I replaced the cable today. Same issue.

[dskall]

Re: TCL 40FS3800 Stuck in Screen Test Pattern

Do you have a good ground

[Louis82]

Re: TCL 40FS3800 Stuck in Screen Test Pattern

You know, I was wondering the same. Can I attach a wire from the circuit board to the screen metal shield? FYI Power cord has only 2 legs.

[Th3_uN1Qu3]

Re: TCL 40FS3800 Stuck in Screen Test Pattern

You know, I was wondering the same. Can I attach a wire from the circuit board to the screen metal shield?

Yes you can.

This is actually a big problem on some ASUS laptop LVDS cable - they use the silver conductive mesh tape which the cable is wrapped in, as the only ground of the circuit. Seen it cause quite a mess of an intermittent issue. Ran a wire from one connector all the way to the other, soldered on both sides, problem solved.

[Louis82]

Re: TCL 40FS3800 Stuck in Screen Test Pattern

I used al alligator from tape to screen (metal) still the same. Pic is attached.
I'm starting to think that I damaged the screen.

[Louis82]

Re: TCL 40FS3800 Stuck in Screen Test Pattern

I believe that when I reversed the cable, I probably didn't put the cable correctly and the pins did not seat correctly and caused a short that allowed the tv to go into screen test pattern. How do I get out of that?

[Louis82]

Re: TCL 40FS3800 Stuck in Screen Test Pattern

Here are two pics of the immediate components that are located right where the LVDS connector goes on the screen side. Maybe you guys can see something.

[vinceroger69]

Re: TCL 40FS3800 Stuck in Screen Test Pattern

ignore, just seen you have already tested the panel pcb fuse