Computer Restarting randomly

Ok, for the past few weeks im having this stupid problem that my computer just restarts randomly. Ive disabled automatic restart on system failure in XP, the problem doesnt seem to be in the OS. It just restarts, i have a few blinking lights on my motherboard near the wifi thing..and then sometimes the total supply just dies. Is the powersupply(SMPS) drawing too much power or something ? i have a 400W smps and i have 2 hdds, both sata, one dvd rom, 7900 GT. Once i found the fuse on the spikeguard in the set position so i had to push that button to get it working again, could this be a problem with the electricity supply? my system is pretty new..i got it just some weeks ago. Also when it restarts, i hear a kind of buzzing sound from somewhere inside the cabinet..

This is my motherboard -> http://www.shopbot.ca/p-43078.html

From my expirience - just random possible reasons:
1. Insuffitient power supply
2. Problems with the cooler of the power supply (some power supplies shut down if they cannot achieve the desired speed of the cooler)
3. Not stable incoming power
4. Virus (try not to boot OS and see if the problem still occurs)
5. Corrupted service

Have you tried to disable WiFi?

My brother has been experiencing the exact same problem with his system (specs not available ATM). I've disabled all fancy BIOS settings I could think of and turned off auto-restart with no success. He also recently installed a WiFi card and has had some conflicts with drivers that led me down a fruitless path. So far all we've come up with is it seems to happen in relation to bumping of the case (or through the desk). Due to this, I suspect the PSU, with nothing but conjecture as my evidence.

Attempt to compare bumping/touching of the case to reboots for now and I will attempt get a hardware spec of his system to compare to yours (tomorrow possibly). Perhaps a matching piece of hardware will give us both a clue.

From what I've heard, I would suspect the PSU first.

When a PSU is dying, in order from healthy to sick...

• Computer restarts sometimes.
• Computer turns off sometimes.
• Computer no longer turns back on on the first try.
• Turning on the computer is like trying to start a lawnmower.

The only way to test really is to use a multimeter. Because it is unlikely that your new computer has a bad PSU, the wall supply might be to blame.


One other thing that can cause reboots is temperature problems, which I've also had in the past. Heat problems are sometimes freezes, sometimes reboots. Nothing in the computer should be too hot to leave your finger on there for a few seconds.


The buzzing sound...
Almost always, buzzing means a loose ball bearing in one of the fans. If that is the case, it's just a matter of time before that fan dies.

> Once i found the fuse on the spikeguard in the set position so i had to push that button to get it working again
My guess is that it's a combination of poor electrical supply, and running the power supply close(?) to it's limits. The more power you draw from the supply, the more sensitive it becomes to transients on the electrical supply.

Things to try
- reduce the power being drawn, by unplugging some non-essential hardware and under-clocking the machine.
- get a better PSU with a higher output rating. With a lot more head-room, it will be a lot less stressed in normal use, and be able to absorb any transients better.
- get a UPS (or a filter) which can smooth out the electrical supply.

Have a look around the house / neighbours to identify things with large electrical motors (fridges, vacuum machines, water pumps, air-con) as these often generate pretty big spikes (when they start up) back into the electrical system and perhaps back to your machine.

Quote:

---

Originally Posted by QuestionC

The buzzing sound...
Almost always, buzzing means a loose ball bearing in one of the fans. If that is the case, it's just a matter of time before that fan dies.

---

Depends on the sort of buzzing, but if you mean like an electical buzzing sound it could be 2 loose terminals that aren't contacting properly.

The first step is always to determine whether it's software or hardware, random restarts could be either.

Download and burn a Knoppix CD. Boot it in your system, play with Linux for a few hours. If you get the restart, it's definitely a hardware problem. If you don't get the restart, it's unfortunately inconclusive.

If it is hardware, random restarts can be caused by so many parts that it can be difficult to narrow down. In my experience, it's usually a bad motherboard, unless you're overloading the power supply. Unhook some of your less important and power hungry devices to see what happens. Bad RAM is an excellent possibility as well.

I dont know, its really random, now it hasnt happened in the last 2 days and the computer has been either running or in hibernate mode all this while..So im very much inclined to think that its an issue with the power supply coming from the electricity board in the city..it turns out that just a few days ago they replaced a bad transformer in our area, so that could be the reason..i ll still wait for a few days and see if the problem reoccurs.

Ive checked the temperature, CPU at 35 degrees and motherboard at 48..its a core two duo proc, E6420. Im going to disable wifi soon i guess..

It may be a virus. I once had a virus that randomly restarted my computer and it was hidden so well that I could not find it for weeks.

Well, its not a virus, the computer restarts even during bootup, ive observed a few things in the past few days..when the computer restarts, the power leds on the mother board go on n off once or twice n then remain as they are..so i changed the SMPS, i thought that would work, but no, i still get the problem..now a days it is more frequent..i dont know, but yesterday when it happened, i observed that for a few seconds the power to both the motherboard and the monitor had gone away..so it might be due to the spikeguard that i have, so as of now i have given power to the computer directly from the main powersupply and not through the spikeguard..i dont know if that will work, should i take the motherboard to the service center ? could it be a motherboard problem ? somehow i dont feel it would be, but im not sure..i got my old powersupply replaced for no reason it seems :( this is really p***ing me off, i cant even find the root of the problem..ive changed the ram, the powersupply, booted with minimal components attatched..still doesnt work..any idea ?

@lightatdawn, can you tell me the specs of your brother's system ? i ll try looking at the touching of the case thing for now, somehow i dont think ive been touching the case much..so i dont think the problem lies there.

It does indeed sound like "bad power into the computer" - you may want to look at getting a "UPS" which is a box with a big battery and that you plug in between power socket and your computer, it "smooths out" any dips and bumps in the power supplied to the computer, and will also allow short power-cuts (or longer power cuts if you pay more for it).

--
Mats

I dont know, i live in an area where the powersupply is pretty nice and there are hardly any powercuts, like hardly 5 times in a year for not more than 1.5 hrs each.. but yeah, i do think it could be because of the power thing..somehow i dont think its a problem with the motherboard, but im in two minds whether to take it to the service center or not, can anyone tell me whether with the current symptoms, can i rule out that its a problem with the motherboard ?

No, there's no way to say (from where I'm sitting a few thousand units of distance away) whether your motherboard is OK or not - and unfortunately, intermittant problems like this are often hard to track down - you can almost certainly "bet" that the problem isn't going to happen when it's at the service center.

My suggestion for a UPS is not to cope with power-cuts, but to smooth out those dips that may cause your system to restart. If you think that the source of the problem is the power coming into the computer, then a UPS will "sort that out" by supplying a nice, smooth power.

--
Mats

Quote:

---

Originally Posted by PING

Well, its not a virus, the computer restarts even during bootup, ive observed a few things in the past few days..when the computer restarts, the power leds on the mother board go on n off once or twice n then remain as they are..so i changed the SMPS, i thought that would work, but no, i still get the problem..now a days it is more frequent..i dont know, but yesterday when it happened, i observed that for a few seconds the power to both the motherboard and the monitor had gone away..so it might be due to the spikeguard that i have, so as of now i have given power to the computer directly from the main powersupply and not through the spikeguard..i dont know if that will work, should i take the motherboard to the service center ? could it be a motherboard problem ? somehow i dont feel it would be, but im not sure..i got my old powersupply replaced for no reason it seems :( this is really p***ing me off, i cant even find the root of the problem..ive changed the ram, the powersupply, booted with minimal components attatched..still doesnt work..any idea ?

@lightatdawn, can you tell me the specs of your brother's system ? i ll try looking at the touching of the case thing for now, somehow i dont think ive been touching the case much..so i dont think the problem lies there.

---

Check to see if your bios is configured to check for viruses. You say its not a virus but I say it is.

Okay, i think i got the problem..its with the spikeguard..i connected my smps directly to the mains and the monitor to the spikeguard, my monitor shuts down in between sometimes, but my computer is working perfectly fine other than that :)