AvalonExtra

Hello all, I was wondering if anybody has come across this issue. Sorry this is a bit long winded. It was one of those days. Got the old 203 scrapped, it just wasn't worth repairing. But I saved the audio 10 cassette head unit. Thought it would be a nice trinket to hold onto.

Wired the unit up and up popped the PROG lock. No way of entering a code since it was matched to the car can bus. After going through numerous threads the solution appears to have it wired up and reset with the star diagnostic system and a file from Mercedes. Car was long scrapped by then.

So, after bumbling through more threads and videos somebody on YouTube suggested desoldering the code chip and that it works without the chip. No no, not true not true, not with this unit atleast. After carefully desoldering the chip the unit completely died. It draws a current but nothing else happens. After spending an eternity soldered the chip back with no change I'm at a complete loss. Anybody come across this?! Anybody have any suggestions on a fix for my sentimental headunit?! Any help would be much appreciated!!