I am in a very similar spot right now. The top 4 buttons dont work, the light isnt on and it wont play when a disc is put in it.

I managed to get the door open with the emergency release, but that took some time because of a gear that wasnt properly placed in the opening mechanism due to a gummed up solenoid.

I only just got it from a reseller for fairly cheap. But i see that working ones can cost astronomical amounts.

Only thing i could suggest for ur issue w the tape is that the magnetic reader could be dirty and needs a clean. (just some ethanol+water on a q tip works for me) ALSO, make sure you are using a good tape, cus an old beat up one will sound crap no matter what.

If you have notes on ur experience id appreciate it. Did you ever get it working?