Just bought a '90 with a factory Premium Sound JBL casette and CD player, neither worked, so I replaced the casette with one from my '88 Mark VII, it worked fine, but I plugged the CD player, and no sound is produced. I tried the original deck without the CD player, no sound, it just turns on-so my question is, does anyone know where the problem lies? (besides the obvious remark that I should replace the CD player and the casette)