Ok, so my Mac is acting up. For reference it's a Dual 1GHz PowerPC G4 (mirrored doors) running OS X Panther. Over the last few months when booting up I would sometimes get a grey screen with foreign writing on it (was told this is Mac's "fatal exception screen"). If I turn off the computer a few times it would eventually boot up. I turned it on the other day and all I get is a grey screen with a folder in the middle that flashes between a finder logo & a question mark. Never seen this before, but I was told that there might be a problem with my hard drive. So I bought a new hard drive and Leopard, went to install it, and it crashed before it even started installing. Someone has now told me this could be a logic board problem? Any input would be greatly appreciated.