Hmmmm, everything worked fine before the detail. I actually have some spare becker units I picked up from the salvage yard while I did the aux jack mod. Is the tape belt something I could replace? Right now there is just a gutted tape in the player, all the audio is coming strait from the aux jack I soldered in to the tape audio lines. If the tape belt is a hardware feature that's failure is preventing me from even accessing the tape aspect of the head unit though, maybe I can replace it?

DIY Ipod auxillary input on 2000-2002 Benz Radio w/PICS - Mercedes-Benz Forum

^There is all the information regarding the aux jack mod I did months ago. It's been working flawlessly for a long time now.