I just got it in today and I've looked over the motherboard and parts.  The battery hasn't exploded but it was dead (blue label Inorganic brand) I replaced it with a good purple battery. Removed the extra memory, the only Nubus card (ethernet but has 15 pin connector and old base-2, guess someone was too cheap to pick up Apple transciever and use onboard ethernet?~) and disconnected the hard drives to rule out faulty short.

However it doesn't boot up. No chime, no light, nothing.  I don't have 800 or 8100 mobo to test with and I don't have extra power supply of these type to swap with. Where can I start poking for problem?