Not a mod as such, more a repair.

I picked this thing up for free. No cracks in the panel, so I figured I might get it running.

When I plugged it into a DA G4, the thing was utterly dead. Wouldn't even try and boot. Brief flash behind the displays power button. I took it apart to check for loose connections, nothing obviously damaged.
Tried it again with a G4MDD same thing. The power button would not even light up when pressed with the display connected. In the MDD, I noticed that something started to make a regular ticking noise in or near the front panel board when pressing power with the display plugged in. Had to unplug the power to stop it.

Any thoughts on how I can get this thing working?
Anyone know where to get parts for one of these?