[shorod]

Does anything about the radio/cassette player work (display, etc)? There may be a fuse in the deck, or the fuse for the Rear Control Unit (RCU) in the trunk may be bad. If the display works but there is no sound, suspect the RCU. If the display doesn't work and the cassette mechanism won't accept tapes, then you have a power issue to the deck as you suspect.

How good are you at tracing wiring diagrams?

-Rod