Power supply problem?

What PSU do you have?

It's a Dimension E520 w/ the standard Dell PSU, I believe it's 350W. I only use the system for development work.

Could be the PSU. Most manufacturer PSU's are not of the high quality sort (though Dell and HP are getting better).

Can you test it with a different PSU?

It's either a power supply problem or possibly a problem with power management settings. Remember, you reinstalled the OS on a new HD.

After installing the new HD I originally installed Windows Sever 2008 R2 Server Core (Server Core doesn't install the GUI only a command prompt) It was the first time I'd run server core and I thought I that mybe I had screwed something up so I did a full install of Sever 2008 R2 and still had the problem. Thinking it might be an imcompatibility with R2 I wiped the disk and installed Windows 7 (which is what the system was running when the HD failed) and still had the problem. I've checked OS and BIOS power settings and everything looks OK.

I don't have a spare PSU lying around to test with. I'd have to buy one or pull one out of one of my other systems. My concern with doing this is that Dell used to use different pin-outs on their PSU. I'm concerned that I might fry my mobo.

A different PSU shouldn't be a problem. Modern motherboards are usually 24 pin (some still 20 pin) and modern PSU's usually have a 20+4 pin power adapter to allow compatibility with either 20 or 24 pin.

True some older Dell's did some weird stuff but the Dimension E520 is beyond that era.

Thanks Viper. Your right. It looks like Dell has stopped that non-sense. I searched the Dell support forum and found some posts indicating that the E520 can take a standard ATX PSU.

I guess I'll go get a new PSU tomorrow. Hopefully that'll fix the problem.

It turns out the problem was caused by a D-Link DGE-530T network card. Installing the driver for the card fixed the problem.

Thanks for the assistance.

Glad to hear you've got it all working again.