|If your mboard is not new (usually the mboard is at least 2 years old when this happens)......|
Some mboards develop this problem - electrolytic capacitors were installed on them that were not properly made, and they fail eventually - the mboard manufacturer didn't know they were improperly made at the time the mboard was made.
Open up your case and examine the mboard to see if you have bad capacitors, and/or other findable signs of mboard damage .
This was the original bad capacitor problem - has some example pictures.
History of why the exploding capacitors and which mboard makers were affected:
What to look for, mboard symptoms, example pictures:
Home page that site
- what the problem is caused by
- he says there are STILL bad capacitors on more recent mboards.
Pictures of blown capacitors, other components, power supplies, fried Athlon cpus, etc.: