...power out...reboot...power out...reboot...turn off...turn on...no text on screen, motherboard not booting...cmos battery out/in...no booting...remember strange sound from hard-drive, take out hdrive. cable, reinstall...board boots, hdrive. works.
An example of how some computer crashes can be fixed. Suggest you unplug all cables, and re-plug before you trash the motherboard.