Well I'm not really sure what is wrong with this power mac I bought it has no CPU so I bought one which hasn't arrived yet. If I try to power on the unit without the CPU wouldn't the fans at least start up? I've read that it could be the pram battery. Any advice for me installing the CPU with some arctic silver 5 thermal compound? I've never installed a processor before... But if it is the PSU I'd like to know because I can get one cheap from the same place I bought the CPU. Many thanks in advance.