I can usually manage to sort out hardware problems one way or another, but this one has me completely stumped. I'll try to explain everything I've tried, and hopefully someone has some ideas.
I assembled a new computer in late 2007 made up of the following components:
Gigabyte GA-P35-DS3R ATX LGA775 motherboard
Intel Core 2 Quad Q6600 Quad Core Processor LGA775 Kentsfield
EVGA E-GEFORCE 8800GTS 500MHZ 320MB video
Antec Sonata III Case
3 Scythe S-FLEX SFF21F 120MM Cooling Fans
Thermalright ULTRA-120 Extreme 6 Heatpipe Cooler
OCZ Platinum XTC REV.2 PC2-6400 2GB DDR2-800 memory
2 LG GSA-H62N SATA DVD+RW 18X8X16 DVD burners
2 Seagate Barracuda 7200.10 500GB SATA2 3GB/S 7200RPM 16MB Cache hard drives
When I first tried to use it, it was horribly unstable. It turned out that the motherboard was defective. I
RMAed for a new one, and then it worked much better. However, there were still all sorts of bazarre problems. It would not boot up if more than just the keyboard was plugged into the usb ports (booted up fine if you unplugged everything). The bios would often reset and it would reboot on it's own. It would randomly freeze up with no particular consistency... and the DVD trays would constantly open and close randomly on their own every few minutes. I contacted the vendor and they shipped me yet a third motherboard. This didn't solve the problems at all, and it started getting progressively worse.
To make the long story shorter, here's where I'm at now:
When I turn on the computer, it will growl and try to start up, then will shut down and try to start up again,
growl for a second, then restart. It will do this over and over until you cut the power at the power supply.
However, if you come back the next day, it will start up fine and boot right into Vista. It will run for a few
hours without any problems. I can stress test it with Prime95 for several hours without fail. The cpu
temperature is at 31 degrees on idle and up to 52 degrees at full load. However, it never dies while I am using it. However, when I just leave it idling and come back in a while, it will be froze up solid. If I try to
re-boot it, it just growls again. I can come back the next day and try to boot it up, and it will just growl and
keep restarting. Yet, if I try again later, it will boot up and be fine for a few hours again. Somewhere in the middle of all this, one of the hard drives died (will not spin up at all and is not recognized), so that took
out both drives, since I had them in RAID. Therefore, to simplify things, I disconnect everything else,
including all hard drives, and I installed a new single Raptor drive. It booted up and I was able to install a
fresh copy of Vista on the single drive. Everything was working fine, so I thought that maybe the dieing hard drive had been the cause of the problems. However, I left it alone for a couple of hours, and when I came back it was frozen up solid again, and would not re-boot.
I have had it in to the computer repair store, where they checked for over heating and voltage tested the power supply. They are at a loss, too. I replaced the power supply with a bigger (better) 650 watt one. I replaced all the OCZ RAM with new G.Skill DDR2-1000 memory. I initially was using it with four 2gb sticks (64-bit VIsta). However, I have tried each individual stick separately in each different slot. I replaced the video card with a Galaxy 8800 GT 600mhz 512mb. I have tried to get it to at least power up to the bios with no devices connected other than the power supply and video card. I normally have it connected to a large UPS, but I have also tried it plugged in to different outlets in the house on different circuits.
The following are all the steps I have tried to resolve the problem, without success (all problems occur at
stock settings):
1) Tested power supply (with two different PS testers)
2) Replaced power supply (new 650 watt)
3) Replaced RAM (with different brand)
4) Tested with 4 different individual sticks of ram in different slots.
5) Tested with multiple video cards (different brands).
6) Tried to boot without any drives or extra cards installed
7) Cleaned, re-greased, and re-seated cpu heat sink
8) Replaced heat sink
9) Replaced hard drive with single, non-raid drive and clean install of Vista. It stayed running long enough to install Vista, then crashed and wouldn't reboot.
10) Tested with motherboard outside of case (sitting on cardboard to avoid any possible shorts)
11) Replaced botherboard (twice)
12) Re-seated cpu
13) Reset bios via jumper
14) Monitered cpu temperature
15) Stress tested cpu
Is it possible that I have a defective cpu that is causing the bizarre behavior? It seems to be the only thing I haven't replaced. I am really confused by the fact that some days it will run fine and other days it won't. The problem does not appear to be related to heat, as I can have it turned off for days, then try to start it, and it won't boot... then a few hours later, it will. If anyone has a theory, I'm open to any suggestion, as I've run out of ideas. Sorry for the long winded problem description. I just thought it would save time if I
explained everything I've tried.
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