My PC restarts all by itself

[sandeepk]

Hi guys,
This is my first post in this forum. And i am not very happy to start with a problem. My PC restarts all by itself and i have no clue abt the reason. There isnt any virus. I believe its a hardware problem. And this restart usually happens wen i run multiple programs and sometimes it happens wen my net and music are both on. I am not able to figure out the exact reason for this.I have also run the memory test several times and there wasnt any error.
And also I have a Sata HDD and it is being recognized in the PIO mode and not the DMA mode.Has it got something to do with the restart problem.
Please throw some light on this issue.Thanks in advance.

[BeastOverlordH6]

This happened to be before, back when my heatsink was loose--where the computer would reboot whenever the heatsink came off the processor by the smallest amount.

If your heatsink is well-mounted and tight, then I'd look to the hard drive or possible lack of sufficient power.

[dcc]

It would help if you provide us with some information about your rig. What make and model, how much RAM do you have, how large is you hdd, what kind of free space do you have on it?

[sandeepk]

My PC config:
P4 2.8 GHz processor
Intel D865GBF chipset
767MB DDR-SDRAM (400 MHz)
160 GB Sata HDD and free disk space is around 13 GB
IOMEGA DVD burner
NVIDIA GeForce FX 5200 128Mb AGP

[dcc]

You still haven't told us what make and model your computer is, or what the motherboard is. It would also help to know what your OS is. How are you using the SATA hdd on a system that uses an IDE cable?

PIO mode is normal, you would use the DMA only in applications like reading or burning a DVD where it will allow you to bypass the CPU.

Your RAM being SDRAM means your computer is old enough that it's possible that you are using FAT files on you hdd, with a hdd as large as 160GB could be a problem if the partitions are larger than 32GB.

Another thing to look at is the PSU, it can cause your system to restart if it's over taxed or the voltages of the different rails isn't as rated. Like the 12V rail only producing 11.5V.

It could be heat related, are your fans working properly? Case fan, PCU fan, PSU fan. If you haven't cleaned the inside of the computer you might want to do that, blow off the boards, heatsink and fan assembly.

What sort of programs are you running when you say that you're running multiple programs. Is there any specific combination that you know will cause it to restart?

How did you test your RAM?

[sandeepk]

Its is an assembled PC. The motherboard as i said is an Intel D865GBF. And the OS is Windows XP professional edition with SP2.
I have 8 partitions on my HDD.2 of them are 40GB and 2 are 30GB.
All the fans are working fine. I have also cleaned the inside of the computer and removed the dust on the heatsink. But i find that the system temperature in the BIOS is showing around 128 deg celcius.Is it an abnormal figure??

PC usually gets restarted wen i am browsing over the net.
Over past few days, i have been putting the system idle all night jus to test if it would restart, and to my surprise, it got restarted every time although there werent any applications running.
And DVD burning is taking too much time and most of the times the burning isnt successful.I feel that becoz of the HDD getting detected in the PIO mode.
I used the memory test at www.memtest86.com. I have run around 25 passes and there wasnt any error.
Please lemme know if any other information is required.
Thanks a lot.

[dcc]

Its is an assembled PC. The motherboard as i said is an Intel D865GBF. And the OS is Windows XP professional edition with SP2.
I have 8 partitions on my HDD.2 of them are 40GB and 2 are 30GB.
All the fans are working fine. I have also cleaned the inside of the computer and removed the dust on the heatsink. But i find that the system temperature in the BIOS is showing around 128 deg celcius.Is it an abnormal figure??

PC usually gets restarted wen i am browsing over the net.
Over past few days, i have been putting the system idle all night jus to test if it would restart, and to my surprise, it got restarted every time although there werent any applications running.
And DVD burning is taking too much time and most of the times the burning isnt successful.I feel that becoz of the HDD getting detected in the PIO mode.
I used the memory test at www.memtest86.com. I have run around 25 passes and there wasnt any error.
Please lemme know if any other information is required.
Thanks a lot.

But i find that the system temperature in the BIOS is showing around 128 deg celcius.Is it an abnormal figure??

Not if you're using it to cook you dinner.:eek: Have you checked to see if there is a new version of BIOS available for that motherboard, from what I've read it look lik a earlier version can porduce erronious temps. Have you overclocked this machine?

Another thing to look for is bad caps on the motherboard, epsecially around the PSU connectors.

Another issue that I've read about with that motherboard is that the HSF may be inadaquate, if your computer is still under warranty you might see if they will upgrade it for you. If it isn't you might try installing a better HSF. How many case fans are you running?

You should have at leat two, one in the front of the case to draw fresh air in, and a second in the rear to exhasut the air.