Repair-It

https://mbworld.org/forums/s-class-w221 ... olved.html

Glad I found this. Going to take mine out and apart and gently clean the dust. I wonder if there is a way to install a small filter but that would reduce airflow. Maybe a higher power fan....

Or just clean every once in a while. It's crazy that the dust causes shorts. I thought the issue was the dust makes it overheat. Or maybe it does that, too. Mine has no issues but apparently issues are very common and this seems to be a pretty common cause. Or maybe THE cause?

I found this
https://youtu.be/LP4ejFlCQDw

Amplifier repair. I asked him about cleaning and he said yes, clean the dust. But he also recommended a PCB lacquer coating which is an interesting idea. Might save the board from shorting in the future. Now if I could only find some anywhere...

This isn't lacquer but it seems to be the same type of product
https://www.amazon.com/MG-Chemicals-Pre ... B088GP981V

Or is is lacquer? Here is the spray:
https://www.amazon.com/MG-Chemicals-419 ... 9741&psc=1

That was a bit of...fiddling. It wasn't hard to get into the area. Maybe easier than my E55 though I prefer the plastic retainers my E55 uses on the rear trunk hinge cover. These use two standard plastic pop rivets, and then under the plastic is those plastic push pins. Since it was super cold I broke two. But there are like 4 more so whatever.
Anyway, once in the driver's side 1/4 panel area, it looks like this.
Check out the trunk struts.
Then it was a bit of a struggle to realize how to pull the amp out. Remove a bracket for the voice control module to get access to one of the nuts for the amp bracket. Then you have to snap some zipties that hold some wires in various places. Disconnect connectors on top of the amp and then 2 BNC plugs plus 2 more connectors from the bottom. It's all awkward and you can't just yank on stuff. But I got it out.

Then it was fun to figure out how to get the amp cover off. I tried removing those four T-9 screws on the heatsink but that wasn't necessary so I put them back. The cover just sort of snaps off after some prying. It's harder than I just made it sound. Once in, disconnect fan plug.

Before cleaning. It wasn't that dirty. But I used an old toothbrush and some air and lightly scrubbed the board to get the dust off.
I also blew out the heatsink and I didn't see any dust at all come out of there. My assessment is this was relatively clean but I'm glad I took care of it. The fan was running about 2 minutes after I shut the car off so that's what made me wonder. But now it's clean.
I don't know if this is the original amp or what. If so then I guess once every 80k? But it could be a few years old for all I know. I'll probably revisit in a number of years.

Some barcode sticker fell off.

Thinking about it I might be able to do a lazy clean out by shoving my air chuck tool through the fan and giving it some good douches. Any dust should come through the heat sink area. Maybe? Would be a hell of a lot easier.