After my cassette player in my 1991 740SE started a slow decline and then nothing but switching sides back and forth, back and forth..., I checked these forums and others to determine what I was up against. After determining that it might only be a belt problem, I took the unit out and apart to expose the belt. Manually turning the drive pulley caused the belt to turn everything that it was supposed to turn. After taking a digital picture of the belt run, I removed it and examined it under a magnifying glass. It looked OK and felt OK, if a little loose in the track. I twisted it 180 degrees and reinstalled it with a hope for the best. As I was manipulating it along the side of the frame, I noticed what looked like a piece of paper along the frame. What it was was an old serial number sticker, probably from some component of the deck, which was crumbled up and had rubber marks on it. Feeling much more hopeful, I buttoned it all back up and took it back out to the car, plugged it in, and it works like a charm!
Accomplishing this has given me the desire to replace the speakers, maybe...
Accomplishing this has given me the desire to replace the speakers, maybe...