System intermittently reboots

[txtradegrl]

Hey guys. I built a desktop around 7 years ago, and it was running good until a few months ago. What happened was the system began to intermittently reboot itself, at no specific time interval or anything. I thought at first it was the ambient temperature, but I do not think this is the case anymore because right now its 77 degrees in this room, and Im on the computer now with no reboot yet.

I know this isnt a software problem, because it will even reboot itself right after the system posts, but before windows loads. It will reboot at anytime, during booting, right before windows loads, after windows loads, etc.

Another problem that just started to occur, is that I will turn the computer on, and my screen will be black, then go into standby mode, yet the computer is on, and the "busy" light is on. So the screen turns to standby, and after an indeterminate amount of time, the computer will finally boot, then the screen will come on as usual. Sometimes this will take over 5 minutes of just sitting there with the busy light on, so I typically manually shut it down.

I did test the RAM with a memory tester, and during the test there were no errors, and no reboots.

No other hardware changes that I can remember.

This is really driving me crazy...when I am doing something important, it will reboot at the worst times, without warning.

Thank you!!

System specs:

Motherboard: ABIT IC7-G MAXII 478 Intel 875P ATX Intel
Graphics: SAPPHIRE RADEON 9800PRO 128M Radeon 9800PRO 128MB 256-bit DDR AGP 4X/8X
CPU:Intel Pentium 4 3.0C Northwood 3.0GHz Socket 478 Single-Core
Operating System: Windows 7 Ultimate 32-bit (6.1, Build 7600)
Memory: 3072MB RAM
BIOS: Phoenix - AwardBIOS v6.00PG

 

[txtradegrl]

I deleted this thread my mistake, so I reposted it. Also, someone asked what PSU I have, and I have a Antec TruePower TRUEBLUE 480 480W ATX12V Power Supply.

 

[scout_03]

i would check your graphic card since monitor get black means it lost video signal from card

 

[txtradegrl]

Ok i tried the video card in another computer, left it run over night and the computer didnt reboot.

I also changed the power cord to the computer because it was old and thin.

 

[revfarquhar]

I'm wondering if the system is having a hard time reading your hard drive. 7 years is coming up on the end of life for a hard drive. I'd run a disk check, can't hurt.

Although, on second thought the restarting sounds like a power supply issue.

 

[scout_03]

did you use the same video cable for test betwenn the other computer and the monitor ,since you have another mobo on hand follow revfarquhar suggestion for a power supply test

 

[txtradegrl]

About the hard drive, I will run a disk check, just to try and narrow it down.

You mentioned the PSU...the weird thing about the PSU I have, is that from the start, the fan ran so slow that I could barely feel any air whatsoever coming from the back of it. It has a fan, but has always ran very slow, to the point that I always wondered why there is even a fan on it. That being said, I do not have another PSU on hand to try it out, the other computer I have I would have to drill out the PSU, its riveted in.

Scout, I used a separate video cable because the other computer I tried it in has a separate monitor entirely.

What is the likelihood that it could be the PSU?

 

[scout_03]

try the system you have issue with the other monitor and see if you got something