|If you can access bios (setup) that is partly a good sign.|
Might look at bios for any memory tests or power on test. Maybe some quiet setting that you can uncheck to see more of what might be happening.
I might try using safe mode or fail safe settings. There usually is a bios menu choice to put all the settings to some basic settings.
Other than that, I'd try to boot to some bootable cd just to see if it could boot off a disk.
Why did it take me over a year to phone in a problem to ATT?