[Mooreski]

'09 M3, Individual Stereo

Long story short, on one drive my stereo starting making weird noises. Feedback, pops, cracks snaps. Didn't stop when I turned the car off or locked it. On the next drive, there was no sound. On the nav screen it shows that I"m selecting different radio stations, CD, AM/FM, etc but no sound comes out. I checked all of the fuses in the glove box fuse box and they all seem fine.

The next day, I opened the trunk and it smelled like burning plastic. I started pulling trim out and found that my amp was sitting in a pool of water. Looks like the taillight trim failed. I unplugged and pulled the amp out. The boards inside are corroded and the enclosure is as well, looks like it may have been this way for a while. A bit of a smoking gun.

I sprayed everything with electronics cleaner. There are two boards which are connected by a flat cable, like something you'd see in a PC. This was burned at one end from arcing. I clipped the end off and re-terminated. Checked point to point at each end of the cable (on the solder) for zero impedance. Checked fuses and they're all in tact from what I can see. 10V power is still coming to the amp.

Plugged the amp back in and... still not working. I was getting a SOS error so I got a fiber optic jumper and the SOS error went away. but, still no sound and a message that I"m not getting warning tones.

Any ideas on this? Any easy ways to trouble shoot one of these boards?

If it is dead, any good recommendations on a relatively inexpensive amp I could replace with? The stock unit is $1200 new!!

[ctuna]

No easy way I have only seen one person do a a repair on these
and he only had one or two channels out and no water damage.
Water damage to amps is reported here often . Most people don't
have the IA amp. You might try looking for one on Ebay.
There is no cheap substitute for these as no aftermarket company
uses the BMW Most Bus fiberoptic system.(IA or logic 7)
If you wanted to get something else it requires either a Most to analog
converter or programing the Head Unit for analog output.
Since this is a 9 channel amp this requires multiple amps or some compromises. Anything good will be in the same price range if you
decide to go aftermarket.

http://www.bmwlogicseven.com/?p=3837
There are a few places that repair the L7 amp but depending
on how toasted it is they may not be able to.

[Emilime75]

There's an 09 M3 Individual amp on eBay right now.

[Mooreski]

Found it and thinking about pulling the trigger.

Thanks for the info, not what I was hoping to hear but... so it goes. If I get a new amp (or used version of the same amp) is it a simple plug and play or is there coding that would need done?

[ctuna]

There is almost no history of these here as few people have them.
Sometimes on the Logic 7 amp the software needs updating.

[whyzee125]

Originally Posted by Mooreski

Found it and thinking about pulling the trigger.

Thanks for the info, not what I was hoping to hear but... so it goes. If I get a new amp (or used version of the same amp) is it a simple plug and play or is there coding that would need done?

I have EPS and am looking to swap it out for something else. My car is an 08/11 build and the amp works perfectly. Let me know if you're interested.

[Mooreski]

Originally Posted by whyzee125

I have EPS and am looking to swap it out for something else. My car is an 08/11 build and the amp works perfectly. Let me know if you're interested.

PM'd