PC restarts and freezes on regular basis

swinada · Post by **swinada** » Tue Oct 12, 2004 10:36 pm

I build a PC for a friend a couple a months ago everything worked fine. Then about 2 weeks ago she started to complain that her PC keeps shuting down and restarting in the middle of everything. First just once in a while and then last week she wasnt even able to start the system, it would go as far as log on screen in Xp and then shut down and restart. I tought virus or spy ware.
So i took the machine home plugged her in and started in safe mode. Ran Norton and Adaware Search and destroy. Everything clean. She did install SP2 however the problems didnt start immidiatly after that.
So I ran some tests like Sandra burn in wizard etc, had it running for 24 hrs put an other fan in for it might have been heat related. Worked fine as long as it was at my place.
So now tonight I took it up to her place plugged it in startet it up and....as soon it got to the log in screen the mouse froze and the whole thing restarted, over and over again. Tought it might be the old powerbar she used, so plugged the PC in to different outlet. No change.
I'm kind of speculating here, PSupply or Memory, but why the heck would it work fine at my place but not at hers.
Any ideas??? Help??

renovation · Post by **renovation** » Tue Oct 12, 2004 10:49 pm

weak power supply and at her place the voltage could be a little weaker !

Post by **FlyingPenguin** » Tue Oct 12, 2004 11:38 pm

Agreed. Weak PSU. Line voltage at her place might be a bit low or more variable than your place. The PSU can't maintain stable regulation there. I am willing to bet it'll get worse over time until the PSU fails.

Dunno what you bought her for a PSU, but I don't dick around anymore. I go with Antec True Power PSUs and never have a problem. I also like Enermax, but in my own rigs I use Antec Trues.

swinada · Post by **swinada** » Wed Oct 13, 2004 12:28 am

well i put an other "cheap" PS in, same problem, as soon as i get home it works again.
PS came with the case, she wanted a cheap PC so that is what she got. Now I exchanged the PS with the one that came with my PC, it worked fine in mine till I upgraded to an Enermax Noisetaker. So I dont see why it shouldnt work. I also tried different plug ins on different circuits, no change there.
And I dont think she will be to happy if I tell her she needs to spend an other 80 - 100 bucks on a PS.
Could it be memory??? or something else causing this, like a screen???

blade · Post by **blade** » Wed Oct 13, 2004 1:21 am

Finding the culprit for things like this can be very tough. Only way to be positive is to replace each part one at a time, run for a while and see.

It does sound like a power problem though, as fp mentioned.

Worked fine as long as it was at my place.
So now tonight I took it up to her place plugged it in startet it up and....as soon it got to the log in screen the mouse froze and the whole thing restarted, over and over again

What changed? Just using your power versus hers. You can try switching memory and then other parts, but it appears you may be back to square one. If still the same then place your psu in hers again, and hers in yours. To test. That is a hassle though. But that way you'll know.

These problems do suk no doubt. Good luck.

swinada · Post by **swinada** » Wed Oct 13, 2004 1:27 am

Ran prime95 now on it and it craps out after a minute with the error message: "rounding was0.5, expected less then 0.4"
tried to google for this however there is no concrete answe r to this message. Some had bad memory chips other bad powersupply. So I'm back to square 1.

I did try the different rooms at her place, but no luck.
Dont have a extra Memory stick around so I guess I have to pull mine.

JD · Post by JD » Wed Oct 13, 2004 7:46 am

Could also beat a heat issue. This happens frequently with machines at work. Some of these computers sit in offices running 24/7. A fan gets gunked up and things start over heating.

Its always worth checking into.

TruckStuff · Post by **TruckStuff** » Wed Oct 13, 2004 9:00 am

Is the CPU fan still spinning? I was having an issue similar to this a few weeks ago and found the CPU fan wasn't spinning at a normal speed. This sounds hardware related, IMHO.

swinada · Post by **swinada** » Wed Oct 13, 2004 10:00 am

Not heat related, since it happend as soon as it was plugged in at her place. Also all fans are running, installed even an extra one.
I'll keep looking

BillyGoat · Post by **BillyGoat** » Wed Oct 13, 2004 10:15 am

run memtest-prime is mem intensive- i bet u have a bad stick of ram

Post by **FlyingPenguin** » Wed Oct 13, 2004 10:23 am

You don't have to spend THAT much on a PSU. Here's a decent Thermaltake 400w for $40 shipped at NewEgg: http://www.newegg.com/app/viewproductde ... 006&DEPA=0

HOWEVER if you have tried a couple of different PSUs - including a known good one out of your system. it's seeming less likely it's a PSU issue, or PSU alone.

This could get very tricky. Might be a combination of problems - weak PSU that normally would pass muster, but some other component in the system is becoming very voltage sensitive.

If it ALWAYS runs fine at your place, there has to be something different about her place.

You also need to think VERY hard about what might be different at her location. What about peripheral connections? What else is connected to her computer there that is not connected to it when you take it home.

I've seen some wacky things. I've seen printers that have an electrical problem that cause them to short out the USB or parrallel port which will cause system resets or lockups. Ditto for defective scanners. Even a defective keyboard or mouse with an intermittent short can cause this.

Is she using a UPS at her place? Cheap UPS units will fluctuate power when they go bad, or when the battery's weak.

Since the problem seems easily reproducable at her place, I would try to run the computer at her place hooked up ONLY in the same way it's connected at your place (including all the same cables - if you're like me you probably are just taking the tower to your house and leaving everything else there. You have to find the common denominator.

Another possibility is that she has a serious voltage problem at her house. She might be suffering brownouts regularly. You got a UPS you can loan her for a week just as a test? If the system behaves with a UPS I'd say that's the culprit. Then she can call and bitch at the power company, or just buy a cheap UPS on sale.

Even more speculative - has she recently installed anything in the house that might be creating a large, intermittent power draw? Do her lights flicker when the AC or fridge comes on? A defective starter capacitor in an air conditioner can cause a large current load when the unit starts causing a mini-brownout. Again a UPS will prove/solve this problem.

FAR MORE SPECULATIVE: Anything near her computer that generates a large radio or magnetic field? Does she leave her cell phone near the computer? It's possible (though unlikely) that there's a poorly shielded cable (USB, monitor etc) that's allowing radio signals into the case (that's what the bulge in monitor cable is for - it's a radio frequency choke, and good quality USB cables have them sometimes too).

I've seen flourescent desk lamps cause problems too. A poorly shielded ballast transformer puts out a lot of RFI (radio frequency interference).

Hope this helps....

swinada · Post by **swinada** » Wed Oct 13, 2004 9:05 pm

Well it looks like it is the RAM chip after all. Switched the one from my system, and now I am bale to run PRIME95 on her PC's but not on mine anymore. I hope this will fix the problem and when I take it to her place it will be good now.
Anybody know if Crucial warranty is still good even do the Chip was used in a different system then it was bought for?

FP, I was of course talking Canadian Dollars, the best deal i can get on a Truepower is around 75 for the 350W model, so add taxes and shipping and there are your close to 100 bucks.

I'm heading off to her place now and hopefully this will be the end of the story.

Make my self big note in Brain. ONLY BUY GOOD STUFF AND DONT CUT CORNERS WHEN BUILDING THINGS FOR FRIENDS!!!!

Post by **FlyingPenguin** » Wed Oct 13, 2004 9:08 pm

MY MOTTO: "No good turn goes un-punished"

Yeah, I don't build systems anymore - not even for friends, just for myself, but it's not worth cutting corners. Only takes one sub-standard part to make your life miserable.

swinada · Post by **swinada** » Sun Oct 17, 2004 10:10 pm

If I would have had a shotgun handy this PC would be history. It wasnt just the Memorychip, that would have been way to easy. Even do I think the chip isnt good anymore.
As soon as I started it up at her place again, same thing happend. So home I went again and got an old screen, put that on and everyting worked fine. Now I still have to try her screen on a different system to see if it will crate problems.
If there is something wrong with this screen, could I damage an other system by just hooking it up and starting it? What can go wrong in these screens? It is only a bit over one year old Model TTX 1774

Post by **FlyingPenguin** » Sun Oct 17, 2004 11:00 pm

It's possible but unlikely. But yes, you could have some high voltage coming back from the monitor. Very unlikely though that it would be something that would damage another system permanently.

So you're CERTAIN it's rock stable at her place with a different monitor?

Could be the monitor, could be the vid card, or just a rare combination of both.