I belatedly learn that my daughter's Dell E510 has occasionally been failing to open folders or software. Tonight it suddenly gets past the XP splash screen and hangs, that is, after the splash screen, the screen goes blank with the pointer in the middle of the screen and that's all. The four Dell diag lights are off. The HD sounds like it's spinning up when we power on, but after a while, all is silent except the psu fan.

I ran the quick diagnostics and HD diagnostics with no notable results. We took the two 1 GB RAM blades out in different combinations, but it didn't help. We took out the GEForce GT8800 and replaced it with the original video card but it didn't help. We disconnected all the usb devices but it didn't help. We took out the battery on the motherboard and then put it back in (haven't had time to buy a new one yet). We fiddled with all the power cables and connections. The after market PC Power and Cooling PSU seems okay, that is, the fan is running.

I put the Dell installation disk in and booted to it and let it run through the XP setup, but on the required restart it just hangs again.

I'm running the extensive testing in Dell diagnostic now, but it's past all the memory tests without any notable results.

Any ideas? Is the hard drive dying/dead? How would I know? Is the motherboard dead? How would I know? Doesn't sound like a software/virus issue but who knows. She had a booger of a trojan last year, and we had to blank the HD and start over. Don't wanna do that again.
Thanks.

Since first post, did safe mode boot and it stopped at mup.sys, which I think I know may or may not be a software problem, or could be a million other things. any suggestions appreciated.

Eerily similar to my Precision Dell 9150 model, it loads all the drivers of Windows XP Home, but as soon as it's to activate the Hard Drive for formatting, it halts, As it says Windows will begin installing. Never does.

The 4 number lights I presumed were for the 4 SATA contacts on the main board, it detects RAID use or more then one in use, but I could be wrong I guess.
Seems logical number wise.
There's no physical damage to the mobo and BIOS works good, like mine? Memory in different slots is something I check as well, it can go bad.
CPU connection and fan contact are important as well! You mounted an aftermarket HSF?

What you describe on the E510 could easily be either the motherboard or the hard drive. Hard drives are rather inexpensive at www.directron.com, www.newegg.com, www.tigerdirect.com, www.frys.com, www.techdepot.com, www.pcmall.com, and others... where you can often find a 500 watt SATA for under $55, or a 160 GB drive for $40... depending on the day.
When you try the hard drive, and it doesn't work, it will always be good in another computer.

There do seem to be a fairly high number of motherboard failures of the E510. I suppose your computer is out of warranty.

Thanks I will recheck cpu, didn't really fiddle with it. HSF meaning heat sink fan? No, the GT8800 has up to this point run pretty cool. All this crap came down when she was splitting a 245 page word doc into three files, so I wonder if HD just said "enough".

Yep.

I can drag an extra HD over from other daughter's comp. Embarassed to ask - will l have to do a complete XP install on the new drive in order to determine if it works? Probably so.

Others have suggested running chkdsk, but I've got to find a bootable cd. Thanks for the help.

Yeah, others have used HSF meaning the heatsink and fan assembly are attached when moved, sometimes this is not the case. However, most modern multi cores have the full assembly. Mine POSTS but has some issue accessing the drives for formatting, it will try and effectively boot a formatted drive, but not put a loading from disc OS onto the HDD
Not to hijack your problem board, but since this one appears fine, and acts normal, it would seem the board is OK, I suggest in some cases, check the Cap heads for bloating. You are familiar with Capacitors appearence? Once they go bad or leak, the tops bulge out and discolor

In the context of my limited knowledge of how components should look, I could see nothing wrong with the mobo capacitors or anything else.

Partial solution: I pulled an extra HD from another computer and used the Dell Installation Disk and Resource Disk to do a fresh install, and everything booted up fine. Just have to reinstall a zillion things. Slicker than I had hoped.

The old HD, when put into a secondary slot on another computer, was accessible and we could salvage data files. I did not try booting to it - why borrow trouble. All the diagnostic tests say the drive is fine.

So, could be corrupt windows install or a HD slowly going bad. If original problem stays fixed, then I guess it's not the mobo.

The redundancy of extra computers and parts is a beautiful thing that I'm just discovering.

well, I'm back with mobo or PSU questions

I bought a power supply tester and checked the Power PC Cooling PSU that I bought for this machine about a year ago. It came up 11.8 volts on the main connection to the mobo. Is that okay? I bought what I thought was the best.

Then I checked the other power lines and they seemed okay, until I got one of the six prong connections backward and roasted the tester. D'oh!

So everything's fine for a while, but now every time we start the computer it takes two tries. The first time we get a VERY dim image of the Windows splash screen followed by nothing. AFter holding in the power button it shuts off, and then when we restart it does okay and everything runs fine. This morning, though, it took five tries.

So, do you think it's the power supply, mobo, or video card? Or a combination?

Given what raybay says above, is the mobo most likely? How big a pain in the neck is it to put in a new one? Never done it. I've spent so much on this machine, I would hate to have to start over, especially after having to buy a Dell specific power supply.

any comments appreciated.