Mac Iici won't fire up

I have a Mac Iici that won't power up. It worked when I last used it about a month ago. Now, if I press the power switch on the ADB device (I'm using an ADB to PS/2 mouse/keyboard converted and Mac to VGA converter, which has a power ON switch on it) or the power button on the back, nothing. I swapped power supplies with a working power supply from another Mac Iici, but that didn't fix it. I removed the CPU accellerator card and the NUBUS cards, but it still wouldn't power up. Probably a dead motherboard? I suppose I could transfer my hard drive and memory to the other Iici I have, but it has broken SIMM holders so I'd have to shim the chips with folded paper. I think one of the broken holders is the first one, so that makes it hard to shim. Any other ideas of things I can try to revive this Iici? Thanks. - Bob