Why does this computer restart itself?

[stevied]

Hi Guys, I have a comp at the moment that keeps restarting itself after a couple of Min's. I have checked all the fans are working and the heat sink isn't overheating. I have tried a new hard drive in to it and it still does the same. I have tried a repair install and also tried a hd with a fresh install of windows but still the same problem. I have checked for dust, checked for loose connections etc. Any suggestions would be greatly appreciated.

Cheers
Stevie

 

[Bryce W]

First thing, test power supply.

Check the error log under My Computer and see if its recording any issues. Do you know if it is BSODing very quickly? If so, whats the message?

Also, try a BartPE environment like UBCD4Win and see if reboots in there.

 

[joydivision]

I am not quite sure why you formatted without doing all the tests first? This is what I would do

1) Don't bother with PSU testing its not reliable enough unless the voltages are clearly under, I just give it a quick check with the multi meter, if its under I will buy a new PSU and replace it, if the voltages seem fine (which is often the case) I will try it with my test PSU to see if it solves the problem 80% of the time it does.

2) Swap out the RAM, RAM can cause random restarts

3) Check for loose connections/short circuits etc

4) Test it with a linux live CD to see if its a windows problem

5) If its a windows problem start all the usual tests and checks.

I never reinstall windows in this situation as its never usualy the problem all reinstalling may do is hide the problem for a while.

 

[Techie]

It's the Power Supply most likely, replace and you'll be fine. I wouldn't even bother checking the rails.

 

[kisk]

for me, random restarts at different times always point to either psu or memory. memory is easy to check.

 

[B Trevathan]

Booting from a live CD like UBCD or UBCD4Win or Dr.web will tell you if it is a hardware or a software problem, if you can boot and run the CDs for a while than it is software, if it reboots with only the CD running then it is hardware.

If it is a hardware problem make sure you test everything under a load. I would first test the PSU then I would test the RAM one stick at a time, I would also inspect the motherboard for things like swelled or leaking caps.

Are you getting any BSODs?
Are you getting any errors?
What kind of computer is it?

 

[LunchBox]

Let's not forget bulding/exploded caps.

 

[Daifne]

Let's not forget bulding/exploded caps.

Exactly. Last one I had in like this had 6 or 7 bad caps.

 

[lgtechcomputers]

Exactly. Last one I had in like this had 6 or 7 bad caps.

* Yes - PSU testing is very important. A lot of things can start with just that.

Very good point on the capacitors.
Sometimes they are really easy to spot because of leaks or bulging. However, sometimes the bulge is very minimal and it is hard to spot.

One indication, that I have encountered, is when the system runs for a bit and suddenly reboot. Memory tests are really bad which make you think the memory is bad but with a very careful inspection of the system, one can find a very small bulge of the capacitor and bingo.