Hi. Let me preface this by saying that I was a PC person who made 'the switch' about 7 months ago. I always used Macs at work, but I never worked on the hardware like with PCs. The problem: A 400MHz blue-and-white machine with 9.2.2 installed. I'm looking to upgrade it to Panther, but it needs fixing first. The thing is extremely unstable, if it even boots at all. Usually it freezes during boot, however. I ran Tech Tool hardware tests on it and it kept crashing when I tested the RAM. I then tested each stick of RAM individually and then paired them off. I tried different sticks in different sockets to try and isolate the bad one(s), but I had the same problem with every stick in every socket. This makes me think the mainboard is bad. I'd like to replace it and see if there is any improvement, but I've been having a hard time finding one. Am I way off on my prognosis? Any tips?