spontaneous restart

[thomprice]

About 6 months ago, I started having problems with one of my computers, a PIII 850 mounted on an MSI 6309 motherboard. Without any warning, the computer would instantly restart.

My first thought was that it was overheating, but the thermal control in the BIOS was disabled. So I figured it must be a software problem, and I formated and reinstalled Win ME. The problem kept becoming more frequent, until finally, it would happen as soon as all of the desktop items showed up after startup, and if I didn't do a forced shutdown, it would just sit there and restart over and over. Even in Safe mode, it would do the same thing.

I updated and relaoded the BIOS, but that didn't make any difference. It would work fine in DOS, but not in the windows environment. So I tried loading Win 95, and that solved the problem, but many of my periferials weren't compatable. Next I tried Win 98, but it had the same problem as ME. Naturally, XP did the same.

I determined that it must be a problem with hardware, and my first guess was the memory. It had 2 banks of 64, which I took out, and tired one at a time, but that had no effect at all. So I figured it must be the MoBo. I found the same MoBo on ebay and replaced mine with this one which was said to be perfectly functional. The problem persisted.

Next it occured to me that it could be the power supply, so I purchased a new power supply, and that still didn't have any effect. Changing the hard disk also had no effect. So I was back to the memory, and I purchased another memory bank and put it in, but still the same problem.

The only 2 pieces of this computer that I haven't changed are the video card and the CPU. I'm starting to get frustrated. Any ideas?

 

[Charchris]

try changing the fan...

 

[Lax]

Could just be overheating too quickly. Make sure the HS fan is working and cooling it down properly.

 

[thomprice]

I have disabled the thermal control in BIOS. It isn't overheating. The spontaneous restart happens exactly at the same point after the startup, every single time. A shutdown due to overheating would be much more random.

 

[Lax]

Um......disabling the thermal control won't do anything. The processor/PSU/whatever is overheating will shut off simply because it knows it's too hot. That's why the PSU might be overheating, they will shut off to protect themselves from frying.

P.S. No an overheating restart will not always be random. The CPU or whatever it is is heating at the same speed as it always has and reaches the same temp at the same time. So it COULD be an overheating issue. It could also be a fried CPU/PSU/Mobo

 

[Blue]

Is it possible for you too boot into safe mode?

Edit:

Oh ya what's the make/model?

 

[thomprice]

..... So it COULD be an overheating issue. It could also be a fried CPU/PSU/Mobo

Would a computer with any of those components fried work in DOS? I've changed the MoBo and PSU.

 

[thomprice]

Is it possible for you too boot into safe mode?

Edit:

Oh ya what's the make/model?

It isn't possible to boot in safe mode.
It is a PIII 850 on an MSI 6309 MoBo and various other compunents of differing manufacturers.

 

[aniruddha_mohod]

I had also the same problem in one of my pc. I was thinking to replace the motherboard but thank you that you told me that this will not solve the problem. If anybody find its solution then please inform me.

 

[Blue]

It is a PIII 850 on an MSI 6309 MoBo and various other compunents of differing manufacturers.

LOL that was a dumb question eh? Sorry for making you repeat yourself.

Have you tried another hard drive? it's prob. not the problem but it's entirely possible. I've had a HD that would fail and the computer would shut down but no restart (it's also a bios feature to have the computer reboot with power failure). This hd eventualy would not even allow me to instal windows xp anymore and although I did not try it with another windows Operating system it did allow me to instal Susie as well as mandrake linux.

If I had to guess and i'm sorry for guessing here but I would suggest perhaps it's the hd or a power problem but sadly could be a number of things and as you've suggested also the memory. I do figure though that it's not the motherboard failing as it works with windows 95 and it figure it would not if the motherboard had a problem.

 

[mgoldb2]

My first guess would be overheating but we eliminated that being the problem

secound would be bad memory but that been tested.

powersupply next but you tested that already

next audio card drivers but since you reinstalled windows a number of times that proberly not it.

Do you have a USB HUB(or any USB device connected) becuase that can cause random restarts. If so see if the computer work with out any of the usb devices connected.

have you mixed FAT32 and NTFS harddrives(one of each or both on the same harddrive) or mixed FAT32 and NTFS in any way because that can cause radom restarts.

 

[Praetor]

Are the voltage rails stable

 

[thomprice]

My first guess would be overheating but we eliminated that being the problem

secound would be bad memory but that been tested.

powersupply next but you tested that already

next audio card drivers but since you reinstalled windows a number of times that proberly not it.

Do you have a USB HUB(or any USB device connected) becuase that can cause random restarts. If so see if the computer work with out any of the usb devices connected.

have you mixed FAT32 and NTFS harddrives(one of each or both on the same harddrive) or mixed FAT32 and NTFS in any way because that can cause radom restarts.

The fan is working fine, and the heat sink only gets slightly warm. I don't think it is overheating. If I take the CPU out and try to start, nothing happens at all, so the CPU is functioning at least partially, since I can get into DOS and BIOS and through the startup to the point where background programs start to load in windows.

I've tried a different HD and the problem is still the same. Both HDs have been tested in another machine and work fine.

The only USB and audio divices are bundled in the MoBo.

 

[thomprice]

Are the voltage rails stable

I don't have a voltmeter, but I did replace the PSU with a new one, and the problem is exactly the same. I have an industrial electrical system in my workshop/office, which is extreemly stable. Over 440 volts that enter the main panel, there is a maximuim fluctuation of >1%<.

 

[thomprice]

Um......disabling the thermal control won't do anything. The processor/PSU/whatever is overheating will shut off simply because it knows it's too hot. That's why the PSU might be overheating, they will shut off to protect themselves from frying.

P.S. No an overheating restart will not always be random. The CPU or whatever it is is heating at the same speed as it always has and reaches the same temp at the same time. So it COULD be an overheating issue. It could also be a fried CPU/PSU/Mobo

You are absoletely right! I have been able to determine that the CPU is actually getting too hot. I figured it out by underclocking, thus making it run at a lower temp. Taking the speed down to 566 from 850 makes it work perfectly with ME. I could even get it to run at 650. I put a larger fan on and reapplied the thermal paste between the PCU and the heat sink. But that made no difference. It still wouldn't run at its designated speed of 850.

I got everything loaded and the last thing that I had to load was the PC TV, which is the whole purpose of this computer: so that I can have internet and a tv in my tiny room. Then I find out that the PC TV is not compatible with ME.

So I formated again and loaded XP. I was able to get it installed running the processor at 566, which is the lowest speed I can make it go, but it wasn't exactly stable. Now that I have updated with SP2 and put the antivirus software on, I can't even get past searching for a boot record and it overheats.

Is this CPU ready for the trash?

 

[Lax]

Did you make sure to remove the stock pad on the heatsink (if it had one) before putting on the paste?

 

[jshah41]

change ur prosessor

your prosessor is weak and i am sure. i had the same problem once, i changed the processor and everything was fine.

 

[Lax]

He just said that it was overheating (just like I and others had thought).

 

[jshah41]

i had the same problem once. i changed my processor and then everything was fine.

 

[Praetor]

I don't have a voltmeter

Even though its not 100% accurate, BIOS can give an indication

have an industrial electrical system in my workshop/office, which is extreemly stable. Over 440 volts that enter the main panel, there is a maximuim fluctuation of >1%<.

Yes but you can have the best power coming into the PSU but its the power coming out of the PSU that matters

your prosessor is weak and I am sure

wth???