EPS Amplifier - Constant 'hiss' from Driver Sub and General Static

[su_root]

received the car back from some light collision work in the driver rear quarter panel / wheel well area and I'm now hearing a constant hiss from from the sub speaker under drivers seat.

'13 E92 M3 with iDrive

Troubleshooting I've Tried:
- reseated MOST cable at amplifier
- reseated 20-pin black connector at amplifier
- reseated connectors at rear of headunit /CCC unit (I removed the AC ducts and plastic trims to remove headunit)

When I removed the most cable from the amp side, all sounds stopped ofcourse. this leads me to believe the interference is coming in from or being fed to the amp input.

without MOST signal(audio input as I understand) but amp still powered on the hissing and static stops. the speakers are still 'powered on' as the amp is still on. does this mean the amp is not the one introducing the noise?



any next steps would be appreciated! thanks in advance.

[0_to_60]

any updates?

[askme]

Originally Posted by 0_to_60

any updates?

Bump. Eh, I’ll just make my own thread

[Redd]

Most likely the amp. It's a fairly common occurrence.

[0_to_60]

It sure was the amp, interestingly it only happens once it has rained or carwash. But there is no water presence anywhere by the amp.. I disconnected the amp wires, and took it out of the metal holder, interestingly the sound went away, temporarily.

[su_root]

Originally Posted by 0_to_60

any updates?

Two updates...

It was bothering me so much that I caved and paid for repair service. I was told the unit was infact damaged by water as they found oxidation on the power board.

I'm not giving up hope to write up a DIY after all the research I did around general audio amp repairs. I'm now in the market to buy a used/broken EPS amp that I'll take apart and attempt a repair. This is a common issue for Individual audio owners and I don't see why the only available fix is to replace or buy new amp.

[Scrippy]

The corrosion appears all over the audio processing chipset legs. You can remove the two boards from the amp and try cleaning them with a toothbrush and some CRC contact cleaner. Sometimes the corrosion can be removed and sound can be restored and sometimes the damage is already done. When you take the boards out closely look at the chip legs and you will see the corrosion buildup. Make sure the heat sink pads all join the amp case to the chips when you reassemble or heat damage will occur down the road.