Hey commandos,

I just built a 'puter and I was wondering if you could help me trouble shoot a prob I'm having. My computer keeps re booting it self spontainously. Nothing seems to cause it. It just shuts down and starts up. I was suspecting a bad power supply but all voltages are in the green. my 3.3v was a tad high (.12v) but other than that I am well with in th green. I'll answer any questions you have too.

system:
Windows XP
P4 2.4 ghz processer
mach speed Mother board
Western Digital 120gb Hard Drive
ATI 9800 Pro 128mb Vid card
1 gig of Ultra brand DDR RAM
Ultra cooling fans and heat syncs
Ultra 500w power supply
Memorex DVD-R
Broadxent 56k modem
cheap sound card
sony 3.5 drive

One of the viruses from this year caused the same problem.  Is your virus protection up to date and regularly scanned?
Art in KY

well right now I only have limited virus protection but I just turnned this machine on 2 days ago and it was re booting it self before I had it online for the first time.
This shit is driving me crazy!!!!!!

JIM

Well, certainly check for viruses and spyware, even though it is brand new.  Some legitimate software will also install spyware, so it is worth a look.  I use Spybot Search and Destroy, an excellent freeware tool.

But I, like you, suspect bad power.  If the voltage coming off the power supply is adequate and non-fluctuating, try a line conditioner, or use a different UPS or even a different outlet to power it.  At work we had a similar problem and traced it to a piece of equipment in our shop.  Every time the shop worker used the machine, the computer rebooted.  Turns out the PC was plugged into the same circuit as the machine, and when the PC got the spike it died.  Since it just started happening, we theorized that the power supply in the PC had degraded to the point that it could no longer take the spike.  You've got a new supply, but you may still have dirty power.

Also, try removing any cards not strictly needed, like network or scanner interfaces.  I had a bad network card fritz a machine once.

May also try resetting the BIOS to defautls.  Or removing some of the RAM if it is in several DIMMs (try swapping the DIMMs out, using just one at a time).

That's all I can think of.  I hope you get it going...

I fixed it.

Heres what it was.
The system was restarting because the CPU was getting too hot.

Why was it overheating? In my haste to build a great computer I failed to check the compatability of my RAM and mother board.

I was using 2 512MB sticks of 400 mhz DDR RAM while the board was only rated to use up to 266mhz DDR RAM. In a sence the bus speeds of the processer and the RAM were not the same and to make up th diffrence the CPU had to work overtime and created heat (allot of it). The system failed at exactly 41 deg C every time.

The Solution:
I removed the 2 DDR sticks and replaced them with compliant RAM. This in It self helped but still did not solve the problem. The CPU was still over heating but lasting much longer. I then installed 4 case fans and put the cover on. I put the cover on so that I could get a good current of aitflow over the CPU fan/HS.
For the most part I have eliminated the problem.

I still have heat problems when I run intense games and apps but I think a beefier HS and fan will do the trick.

I hope this helps someone avoid the same mistake!

JIM

i'm a computer technican...

there should be no problem running memory rated at a higher speed unless the memory is bad or your motherboard is bad...  a mach speed motherboard?  that shoulds like your problem...

I came to that concusion because the manual said that using memory rated over 266 DDR/ 133SDR would cause unstable preformance.


JIM