Computer Occasionaly won't POST, problem keeps getting worse

[nwrigley]

About a month ago, I came home after being gone for a weekend and wasn't able to get my computer to boot. Power light would come on, fans spin, no POST. My computer is attached to a UPS, so it should be protected from power fluctuations. After powering it on and off a few times, it finally posted, and booted normally.

This behavior has continued since. Sometimes everything is normal, but other times it won't POST on the first attempt. This isn't a problem if the computer goes to sleep, only on a cold boot. The problem has gotten progressively worse with it taking more and more tries. If I see the hard drive access light on the front of the case blinking, then I know it will POST.

I built this computer myself 5-6 years ago and it's been stable ever since. I put a new graphic card in 6 months ago and an SSD drive in 3 months ago, but no hardware changes within a month of this problem.

The problem has now persisted to where it may take a dozen tries before POST I've tried unplugging all drives, reseating the graphics card, and all power plugs. Whenever the system does POST, it always operates normally, no other strange behavior.

Any ideas on what could be causing such behavior?

 

[VirtualLarry]

Probably the power supply.

 

[PowerYoga]

1) mobo going bad.
2) power supply going bad.

Those 2 are the most obvious. Make sure your components are getting enough power on the rails. I've been about 50-50 for mobo/PS when this happens to me.

 

[sm625]

Remove all sata connections. Remove everything but the video cord and the keyboard cord, and one stick of ram. Then repeatedly test to see if it posts reliably. Try testing with and without unplugging the main power cord.