[docgoblin]

My Son's PC began restarting a few weeks ago while in Windows. It will restart at random times. It's not constant, yet it can happen just after booting. Sometimes it will boot and stay on for hours, then it will restart even if no program is running.

I started by disconnecting everything except the C drive, video card and memory. It still rebooted. I ran Memtest and it did two full passes (about 2 hours) with no problem. I then decided to replace the video card (Nvidia 5700) with a new 6200 I had lying around. It seemed to work fine for a few days then it began rebooting again. I put a brand new C drive in and loaded a fresh copy of Windows. As I was doing the security updates it rebooted again. I was starting to worry it was either the Mobo or CPU, which are only about a year old. I downloaded Everest monitor to see what the power sensors showed. The voltages all seem low (CPU Core = 1.4V, +2.5V = 1.4V, +3.3V = 2.5V, +5V fluctuates between 4.4V and 5.3V and the +12V V is wildly fluctuating between 6.5V and 11.4V). The +12V seems way to low most of the time, usually around 7V-8V on average. Could this be the cause of my problems?

Here are the system specs:

Mobo = PCChips M860
CPU = AMD 64 3700+
RAM = 1 GB Corsair
Video = Nvidia GeForce 6200
Sound Card = Creative XFi Audigy
HDD = WD 160GB

The system temps are: mobo around 35 C and CPU around 50 C (Is that too high under no stress??). The CPU fan and heatsink is a thermaltake running at about 1875 RPM.

I'm praying its the Power Supply, but would appreciate any input before I buy a new one. The wide voltage fluctuation really has steered me towards that conclusion, but I'd like the advice of a pro.

Thanks for all your help in the past, present and future!

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This just happened: After another impromptu restart the system booted to Windows then quickly froze (Clock stopped, Keyboard & Mouse unresponsive). It rebooted again. This time I opened Everest Monitor immediately upon booting. The CPU Temp was spiking over 70 degrees Celsius. Everything froze again, then rebooted. Since the last reboot the CPU temp has remained steady at 55 degrees. I was not running any programs when this rebooting cycle started and ended. Why would the CPU temp spike like that all of a sudden under no stress? It's been on for over 25 minutes now and the temp has remained stable at 55. When I ran Memtest it went for almost two hours under intense stress. The CPU fan has been running constantly at 1850-1875 RPM. When I put the CPU in about a year ago I used a high quality silver thermal paste.

This is very perplexing....

[docgoblin]

This just happened: After another impromptu restart the system booted to Windows then quickly froze (Clock stopped, Keyboard & Mouse unresponsive). It rebooted again. This time I opened Everest Monitor immediately upon booting. The CPU Temp was spiking over 70 degrees Celsius. Everything froze again, then rebooted. Since the last reboot the CPU temp has remained steady at 55 degrees. I was not running any programs when this rebooting cycle started and ended. Why would the CPU temp spike like that all of a sudden under no stress? It's been on for over 25 minutes now and the temp has remained stable at 55. When I ran Memtest it went for almost two hours under intense stress. The CPU fan has been running constantly at 1850-1875 RPM. When I put the CPU in about a year ago I used a high quality silver thermal paste.

This is very perplexing....

[docgoblin]

I replaced the PSU with an ANTEC 430 Watt unit (17 Amp on the 12V rail). The system is still restarting. I even blew out the Thermaltake heatsink/fan and applied a new thin coat of arctic silver paste. The CPU temp still seems to climb to 75*C for no reason. I guess I must assume that the processor is dead??? It's never been overclocked and there is a ton of cooling in the case. The case temp never gets over 35*C. I'd appreciate any feedback before I drop more money on a Mobo/CPU combo.

Thanks!