I was wondering if anyone could help diagnose a problem with a Clarion
DRX9255 car cd player. The deck turns on and all the front panel
buttons light, but the display (vacuum fluorescent) is blank. It takes
in a cd and spins it, but there's no signal on the audio outputs. It
also doesn't respond when any of the buttons are pressed, except for
the eject button.. which beeps and ejects the cd when pressed. The
power can still be turned on and off. It's a newer deck, but the face
is non-detachable and it has a true (shaft type) analog volume that's
also the power on/off control.

I tried the microcontroller reset button, and the deck clicks off and
back on, but still the same problem. After reading the repair FAQ and
searching the forums, I'm thinking it could be the microcontroller or
a power supply problem. Does this sound likely, or could it be
something else?

The deck has a large outboard +/-15v DC-DC converter with power and
ground inputs, and then six wires going out to the deck:

In: yellow, black
Out: yellow, black, blue/yellow, black/white, yellow/red, yellow/black

All the connectors and wires test out ok. How should I go about
testing the power supply? From what I can tell, black and black/white
are both grounds, yellow is constant 12v memory to the deck, and
blue/yellow is remote turn-on for the converter. I checked the other
two wires for voltage with the deck on and got nothing on the
yellow/red, and 0.1v on the yellow/black. Also I can hear the
converter "motorboat" or hum quietly when it's on. Is this normal?

Any help or suggestions would be greatly appreciated.

Thanks,
Eric