Amplifier check

Which side are you sitting on?

left - if it matters

If you can't turn the volume right down on one channel and it's a setup with separate amp I'd say the first place to look is the head unit.

And the cables.

Jumper both channels together before the amp... if the signal comes up on the bad channel, it's the head amp or the cabling at the head amp. If it doesn't, it's the amp or the speakers or the wiring between them.

--scott

Good diagnostic - I will try that. Thx

Or simply swap left to right. Trouble is this can be tricky with some amps.

Right, the problem is that all the signals are on a multipin connector, so the easiest thing to do is to jam a jumper wire into the back of the connector.

Note that the multipin connectors _do_ fail. Not too often, but it happens. When you have the one in the trunk apart, pack it with dielectric grease just to keep it reliable in the future.

--scott

Hello,

I suspect some internal IC in the head unit is broken, this is were volume/balance/channel etc are stored. I saw this 2 times in E39 radio's, the IC are NVM IC's, most of the time

What I did solder it out, read it with an NVM reader, get a new one, copy the old info into the new one, solder it back, and you are ready. It's quite a higer level DIY job.

Best regards, Marcel, 525iA @ 364dKm.

Thx - my soldering skills arent as good as yours. How do I get a hold of an NVM reader?