oki ! Thanks for your answer
I'm trying to find something on different forums, somebody on bmwland.co.uk is telling me to resolder something but currently I don't know exactly why (and I'm not really used to solder that sort of little things).
I make a return there if I found a solution

hi,
I have an issue with my BM54 module, on my 2003 320d e46.
Contrary to standard amplifier issue, weel known on BM54, 80% of the time my BM54 doesn't turn on at all (NO ORANGE LIGHT), and even when it turns on (sometimes, but not very often), I now have no sound at all from speakers.
I tried ...