Ok. I will provide the pic and for the test, I would need a multimeter, right? I don't have one. I understand it can be frustrating to try to help a guy who does not know much....

Well I'm way over my head with this thing. I'm looking for a low hanging fruit that could have been fixed and I'm not willing to take it all apart. I don't have the space nor the skills. Now you're right, I could remove the metal plate even though I first decided it was outside the scope of my investigations. Anyway, sorry for being a bit sketchy and thanks for your help anyway. You may well have the last word when I try to ground BL_ERR. Even if you're not there anymore.

I'm not someone skilled doing a comprehensive diagnostic/repair....

Yeah no. Sorry. I just had a clean start before going to dinner. Maybe they are just a bit less easy to obtain than before.

So the situation has changed a bit. For the worse. Since I have disconnected and reconnected the 16 ribbons of the LD board and the ribbon between the LD board and the MB (BMKP), I haven't been able to obtain a clean startup. I have succeeded after getting the boards back from the shop so the worsening seems rather link to my tinkering with the ribbons. Although I can't be sure. And maybe I'm gonna be able to start the TV again at some point.

Anyway, at this point it does not start anymore. I turn it on, the white light goes on, I hear a clack and can see that the backlight seems...

As I said, the communications were difficult. It is hard to know what he really came up with. What he was sure about and what remained unclear. He said the G75 board was the culprit. He said circuits were interrupted around the pics he sent me (see my previous post: the back of the board and then a close-up). It seemed strange as an interruption would not allow the TV to work "sometimes"... This tech guy is well established but I have to agree that what he told me did not inspire confidence.

Your panasonic example feels like something quite similar to my case indeed. Thanks...

I do not see the green and red led. I think that's because I haven't removed the metal plate. Although I think I have had the impression to see a red light at some point when it went wrong. I do my tests in the dark so I can tell if the backlight is on or not through very small openings. The tv installer 8 years ago did not leave the stand of the TV. So It is quite difficult to handle efficiently for tests.

Anyway, I do keep in mind what you suggested and will definitely try that before I'm trough with the TV. Last time I unpinned the other pin on the other connector, I wasn't too...

Yes but for some reason he did not try to change them. He doesn't speak French very well and communications were sketchy....