Adkron,
The original poster queried:
Hi, im about to work on a Windoxs XP machine that reboots itself about every 1 - 5 minutes.
I responded, to which you replied:
Just because it boots does not mean the motherboard is fine. I have had bad mother boards still boot, but certain functions did not work. My specific problem was with the internal speaker. Anytime it tried to send sound to the speaker it would cause a reboot.
Thank you for the mention of possible STOP errors with the internal speaker. If you could cut on of the two lines to the piezoelectric speaker on the motherboard , do you still throw a STOP error? If, once booted under Safe Mode, and using Device Manager and disable support for the PC Speaker under System Devices, do you still have a machine that will not boot in XP Normal mode? Or fails between 1-5 minutes?
Otherwise, the motherboard speaker cannot create a stop error that can stop the machine from booting. This is a PIC or cascaded PIC error, and you need to replace the mother board for failure to handle hardware IRQs. (Which the native driver for the on-board speaker does not use in anyway of importance).
Honestly, I would take this as a very early indication of bad or leaking capacitors on the motherboard.
I agree with you the motherboard is the issue. I disagree with you that you can in the OS create a fatal error, in the absence of more fundamental problems, by asking the internal speaker to beep.
Keep us informed.