LG OLED 55EG9100: is this screen damaged?

[ivan_z]

Merry Christmas everyone!

I got this TV for free, hoping that I would be able to fix it. So far I can't....
The previous owner claimed that the screen is good, the TV has never been hit or dropped or anything like that; physically the screen does look intact.

Symptoms:
When I press the remote, a relay inside it clicks and a second later clicks again (refuses to power on).

When I disconnect the black ribbon cable from the main board and the tcon board, the tv refuses to run from the remote nor from the "on" button underneath the screen, but it turns on when I press the "p-only" button on the service remote. The optical audio ports lits up. But since the tconcable is disconnected, I can't see any picture to tell if the main board works fine.

I "forced it" to turn on by placing two jumpers (Standby3.5V toPower-On and Standby3.5V to DRV_ON); all other wires were properly connected.
It shows garbled washed-out white image on the screen; each time I power it on the image is a bit different. See the attached files.
In this mode I also tested the voltages on the power supply board, and I get nice 3.5 ,12 and 24 volts. So I think the power supply is good.

So is the screen damaged or not, whatdoyouthink?

[Davi.p]

Disconnect main board to tcon band, place the 2 mentioned jumper plus a jumper wire from PSB 12v to tcon 12v input from main board, then turn power on, post results... my guess is bad tcon..

[ivan_z]

Thanks for guiding me!
Done. See the attachment.

I found a 12v pad near the t-con connector on the main board, traced it to the t-con board, then hard-wired it with a jumper cable. I hope that's the same 12v as the one on the power supply board...

The picture looks a bit different, but is still garbage.
Also: previously at every power-on the pictured looked a bit different, now it always shows this very same picture.

[EazyBone]

Looks like 🗑️🗑️🗑️🗑️🗑️🗑️🗑️🗑️

Wait for diah response though. OLED man

[Davi.p]

You have done a different thing, you have to test if the 12v is present at that test pad because that 12v is switched , not good for me..

[ivan_z]

Yes, 12v was present on that pad, and I got the garbled screen, as I already posted.
Just in case, I wired 12v from the PSU to the 12v-input-from-the-main-board on the tcon board (as you ask), and repeated the test. The result is eactly the same: garbled screen.
Interestingly, the garbled image appears when I connect the 12v jumper wire, and then remains on the screen even if I remove the wire.

[Diah]

I "forced it" to turn on by placing two jumpers (Standby3.5V toPower-On and Standby3.5V to DRV_ON); all other wires were properly connected.

this way are wrong.. lets hope you didn't dam danged he MB or the MICOM Chips...
let every things as original connected ... only disconnect the cable of 21V between PSU and T-CON from PSU side..
turn on ( don't use P-ONLY) if you did used this command before... need to press exit on RC first , to exit this limited operation )
give time if its turn on ( the sign the audio Optic port lit red ) if yes....while its ON plug back the socket of 21V. give attention to the screen what will it show... or record it and show here the result

if the set will not turn ON / this unlikely ) there other damage need to do further test

[ivan_z]

Diah, I can't execute your test:
If the tcon board is connected to the main board (as you ask), the tv refuses to start: when powering it on, a relay clicks on, and a second later off.
Same happens if the tcon board is powered (24v from the power supply) or not.

If I disconnect the tcon board from the main board (via the black robbon cable), the tv starts up fine, but, obviously, the screen is dark.

I also did the test that Davi.p asked, see my reply there.

[ivan_z]

Update: I decided to buy a used tcon board on ebay and give it a try. It's about $40, ashipped all the way from China. Will keep you updated.

[Davi.p]

forgot to say you will probably have big problems of previous tv data stored on it, thus image retention, for example a chinese emitter printed firmly on screen, faded.. oled are hard bones..

[Roncruz]

This is my lg oled tv, it has no picture when starting it up its just showing a line in the center i got a lg service remote im pressing the p only button to get it start

[Davi.p]

please post a new thread...