protti

Hello guys, I wanted to ask for some information regarding the 10.25" Display. I installed this monitor 2 years ago, which has never given me any problems. However, in the last month, it suddenly turned off. That is, the backlight doesn't even turn on anymore. When I called the technician who installed it for me, he told me that it was probably the car's auxiliary battery and/or regular battery that was too low. Actually, I have never changed either of them (Indeed the start&stop nor HOLD worked), so I replaced both with original spare parts. But even after changing these, the backlight still doesn't work, while the rest (S&S and HOLD) works, including the radio etc.
It's as if "power isn't getting to the monitor". Before modifying the auxiliary battery, my electrician took it to Mercedes and they said it had 3 errors:

1. 9468 The channel of speaker 2 has an interruption
2. C255 The communication with the central display has a malfunction
3. D185 The communication with the "head unit" control unit has a malfunction

I also tried to reset the infotainment (by pressing the reject disc text for more than 10 seconds) but nothing happened.
What do you think could be the issue? Could it be that since these errors were detected before replacing the auxilary battery, they were not reset and therefore need to be reset? Has anything like this ever happened to you? Thank you very much!