powerbook pismo is smokeing and wont start up

I recently bought two powerbook pismo g3 400mhzs.They both have 10gb hard drives. The ebay seller said one of them didn't work but wasn't specific about what was wrong with it. when i plugged in the broken pismo it wouldn't start up and smoke started coming out through the vent where the hard drive is. I opened it up and found that the hard drive ribbon was what was smoking. I took out the hard drive and the ribbon but it still wouldn't start up. I tried resetting the pram, taking out the pram battery, and reseating the processor card but nothing worked.