Hello All, I have 1988 E30 M3 with the original OBC 13 button. It stopped working several years ago, but I have decided to try and fix it. So far I have done: 1. Check all 4 fuses related to OBC and they all have conductivity 2. Replaced the light bar with a LED version 3. Replaced LCD Screen 4. Replaced bulb that backlights the buttons After all of that, still nothing when I turn on the car. See pictures. Any idea what else I can try? Thanks in advance for any help you can provide.
My guess would be easiest bet is get another one (ebay or bmw used parts places), and swap your new light bar into that. Since it doesn't seem to be powering up (and presumably you're getting voltage at the plug), sounds like something's kaput internally - have never taken one apart to look at the circuit boards, but cracked solder joints aren't unheard of (hello eye loupe and careful hand soldering repair), but also presumably could be anything else related to electronics - bad capacitor, resistor, possible voltage step-up/down regulator, something like that? Unsure as I have zip electrical engineering experience. If you wanted wiring or circuit board diagrams, would take some searching, if they're to be had at all - I don't recall seeing obc internals diagrams in the E30 Bentley manual.
