Desktops forum: Turn Power On > CPU Fan Runs at Full Speed > Screen is Blank

I purchased my Dell XPS 400 system in July of 2006. It ran fine for about a year, until I began receiving the notorious Window's 'blue screens of death' intermittently. At that point in time, it was determined that the infamous Dell stock power supply was failing. Of course, like many other XPS 400 users, this occured within 1 month after my warranty expired with Dell. I spoke with a great friend who is quite knowledgable with PCs, and he suggested that I purchase an Antec EarthWatts 400w power supply (PS), which was up for sale on NewEgg with a great rebate offer.

I replaced the PS, and my XPS ran like new again. Note that when troubleshooting my PC and when replacing the PS, I had removed and re-routed many of the internal wiring of my XPS. I also unscrewed and removed the HeatSink and its shell, exposing the original thermal coatings both on the CPU and the HeatSink. I put it back together and after installing the new PS, my PC never showed any signs of problems. Also note that the Antec PS did not exactly fit like the Dell PS did. The screw holes did not align properly, and it could only be held in by 2 screws (allowing it to wiggle perhaps more than it was designed to wiggle).

Shortly after installing the new PS, I made the decision to upgrade the video card so that I could work with a dual monitor setup. The transition went as smoothly as possible, and the PS seemed to handle the new video card without any issues. All drivers installed flawlessly.

It wasn't until recently, when I removed the side cover of my PC tower to upgrade the memory in the 2 extra banks (2x1GB) that I must have wiggled the power supply just right. After installing the memory and replacing the side cover, I turned the PC on and immediately, the CPU fan went to high speed. I immediately powered down the PC and re-adjusted the PS. I then powered back on the PC, and everything was normal again. With my upgraded memory and performance, I then went on an "install-spree", installing a bunch of memory intensive software. I believe this may have resulted in some driver issues, because the 'blue screens of death' started appearing again after consecutive reboots. So, I resorted to pushing the F8 key at startup, and loading Windows in Safe Mode. I disabled all Services from loading at startup (except for Microsoft's). This got me back in to Windows normally, but the next reboot proved to be the last. Even attempting to load Windows in Safe Mode resulted in the following Blue Screens:

Blue Screen Errors (after each consecutive reboot):
1st Screen: 0X0000008E (0XC0000005, 0X804E13D0, 0XF78D6668, 0X00000000)
2nd Screen: 0X0000008E (0XC0000005, 0X804EF196, 0XBA4FB538, 0X00000000)
3rd Screen: 0X0000008E (0XC0000005, 0X804E13D0, 0XF78E2538, 0X00000000)

After the 3rd attempt, I attempted to change the BIOS settings, to read from my CD-ROM drive first (where I had inserted Windows 7). A screen displayed the following:

{Windows directory}\system32\hal.dll can not be found.

At this point, I realized that I was seriously running out of options. So, I tried to load in Debug Mode, at which point the CPU fan began at a very slow speed, slowly speeding up until the point where it literally sounded like it was going to fly out of the back of the case. I immediately shut down and opened the siding and did some investigating, moving the PS around, removing the HeatSink, ect.

Now, no matter what I do, as soon as I power on the PC, the fan immediately runs on high, and my dual monitors display blank screens with a blinking "_". I've done some research on the forums here at the Dell website, and many have suggested removing the thermal compound from both the CPU and the HeatSink and replacing it with Arctic Silver 5 Thermal Compound. This is where I am at this point in time, I've removed the original compound with a plastic credit card from both the CPU and HeatSink and have cleaned both surfaces with a Q-Tip and Rubbing Alcohol. I will be heading to Radio Shack tomorrow for the thermal compound. I've also heard that the CPU fan may be the culprit. My fan's Dell Part # is D8794 (actual part #: AFC1212DE). But at high speed, the bearings don't seem to be making any awkward noises? Operating temperature is also consistent ranging from 63-73 degrees F.

My hopes are that someone here has been in a similar situation with their PC. I know, up until this point, this has been a lot to read and digest. I truly appreciate everyone's input and/or assistance with helping me find a solution to all of this mess. I'd hate to have to spend money on a new Motherboard... But I really don't think the MB is the culprit, as there have been signs of malfunction leading up to this stand-still.

Thanks in advance for ANY help!

CPU Specifications:
Model: DELL XPS 400
OS: Windows XP Media Center Edition 2005 SP3
Processor: Intel Pentium D
SATA HD: WD3200KS Western Digital Caviar 320GB 7200RPM
HeatSink Model #: TW-OX9694-70090-62K-2231 REV A00 MADE IN TAIWAN
Mfg. Date: 07/02/06
Upgraded Power Supply: Antec EarthWatts 400w
Upgraded Dual Video Card: ATI Raedon HD 4850
Upgraded Memory: Kingston 2x1GB (ensured memory was compatible with my XPS)