I'm going to assume my processor went out on me here, or motherboard.

I usually leave my computer on overnight and woke up to find it off the other morning. I turned it on, fans ran, power light and HD light was on but my screen was blank and in screensaver mode. I shut down and tried again a couple times and after the second or third time I had no power at all.

Thinking my PS was bad I replaced that but had the same outcome as above. I then tried a new video card and had the same outcome again.

Gigabyte 945P-S3 MB
Processor, can't find the paperwork but it is a core 2 duo processor, possibly 2.93GHz but it's 3 years old so maybe slower.

My processor heat sink was pretty loaded with dust so assume I burned it out. I seem to be pretty limited on inexpensive replacements but may try a Pentium Dual Core E6500, not too expensive but I'd hate to be limited in MB's if that is gone.

I put in a cheap 400w power supply to check that, then a Gigabyte HD 6450 video card.

I did pull the processor, all ram, reset everything but also took out the MB to look it over, no signs of burning.

I did try booting up without the floppy and CD drive, same result, as well as swapping ram to different locations, no change.

What should I look at next?

If you do decide to get a new processor, make sure they have a decent return policy if it ends up not being the cpu but the mobo. The E6500 is sort of dated but they have a good price right now. I was looking at them just the other day for a cheap backup unit to replace my 1.8 northwood P4 system.

I still have no idea what went wrong with my PC.

I've tried a new video card but in the PCE slot. For all I know my old card took out that slot, what are the chances on that happening?

Basically, with no hard drives plugged in, nothing except ram and the video card, I get nothing on my monitor, no beeps at all, the power light is on, when the drives were plugged in the hard drive light was on.

I suppose my next step is buying the cheapest refurbished Celeron that will work in this MB and see if it boots.

Any other suggestions are very welcome.

I just sent in my ASUS mobo for service after my PCI E slot took a dump. So it does happen.

No Boot

Well I tried another processor in my PC, a used/refurbished Celeron that was listed as usable on my MB.

I still get nothing, no beep, monitor dark, fans run and HD and power lights on.

So far I've replaced the PS, CPU and video card so I guess a new motherboard is next.

While reading one of the tutorials here I noticed something about the MB using cardboard insulators on the case standoffs. The standoffs on my case are metal but so are the screws and they've been on there for 2+ years, no insulators. I did notice when removing the MB when I first had the problem that the screws weren't very tight and in fact loose, no so much that I noticed the board moving.

Since I really don't want to replace my CPU's now I have to get another 775 board and did find an MSI that will accept both CPU's that I now have. Yikes, I sure hope a new MB fixes the problem.

Case Closed, motherboard failure! I'm wondering if a weak power supply took out my MB as the power supply failed after a couple times trying to get my system to boot.

Regardless, after trying a different PS, CPU and a new video card I replaced the MB, saved all my data, wiped the drive clean and the unit runs great again.