G4 Won't Start (dual 1g, Windtunnel, Panther)



My Mac G4 tower won't start. It's a dual 1Ghz 2002 model with mirrored drive doors (windtunnel) running OS X Panther, with 1G RAM and 3 hard drives (programs, data, editing). I turned off the power bar when it was in sleep mode, and 12 hours later I turned the power bar on and tried to power up my computer. The power button lights up as I press, then goes off when I stop pressing, and nothing else happens. I swapped AC cables, no change. I removed the AC, reset the CUDA/PMU switch, replaced the AC, and no change. I removed the AC, removed the memory battery, reset the CUDA/PMU, replaced the battery, and replaced the AC, and no change. Is it a blown fuse in the power supply? I'm sure I've flipped the switch on the power bar when it's been in sleep mode before with no problems. I don't try to make a habit of this, it's usually by accident.

Perhaps a related problem, my system sometimes crashes in sleep mode, and won't come back up, so I have to press and hold the power switch for 5 seconds to get it to power down.

Also, sometimes my system won't start up when the Linksys Wireless-B router is connected (wired), and unplugging it works fine.

Also, my system often suffers from software crashes "program unexpectedly quit", which has lessened but not disappeared since I replaced the RAM. But this might be due to using unregistered software (ahem).

Also, my system often takes a long time to access the directory of a drive I'm not currently using, even though the energy saver is set to keep the drives active - the little spinny colour wheel goes for about 30 seconds sometimes before the system can access the drive folders. Could these be issues with the motherboard. I haven't got the system serviced by an expert for over a year since I installed Panther.

For any and all suggestions as to how I may get my system working properly, I greatly appreciate it,