Parasound T3 tuner won't turn on

Recently bought a used Parasound T3 tuner and A23  amp together, then bought the P3 preamp on ebay.  Got it all hooked up but the tuner wont turn on.  The on-off button is backlit, but the "P" logo does not light up, nor does the display.  Tried plugging/unplugging - didn't work.  Tried using the remote - nothing.  Tried using a 12v trigger from the preamp - did no good.  Tried resetting the microprocessor per the manual using a toothpick in the unmarked hole near the RS232 jack - did nothing.  Previous owner said it was working when he took it out of service about a year ago, and I have no reason to doubt him.  We are both members of the New England Antique Radio and Vintage Electronics Club.

Any ideas greatly appreciated.


Good suggestion to look for blown fuses.  I actually thought of that after my last post and took the cover off to check.  Didn't see any obvious burn marks or broken wires.  There are three fuses and they all look fine, but I pulled them and checked for continuity -  all are fine.
I wonder if it is the on/off relay?
Not sure what the on-off relay is.  Can you give some details please?