# Desktop PC is restarting randomly.



## jon_12156 (Aug 9, 2009)

So here is the problem:

As seldom as every two days or as often as three or four times a day, my computer will reboot. No windows is shutting down message, no blue screen of death, just suddenly the power is off for about 1-2 seconds. Then it restarts.


Here is what I've tried so far:

I've gone into the windows setting that stops it from automatically restarting on crash (so you can see the blue screen of death), but there never is a blue screen of death anyway.

Reinstalled Windows (Windows 7 64-bit), problem persists.

At first i thought, maybe something is overheating. I checked temperatures of video card and processor. video card was a max of 62 degrees Celsius (usually around 54) and processor was about 48 max.
Not too hot, right? anyway I got into the catalyst control center and turned the fan up to 100% speed on the video card keeping it at like 38 degrees. Computer still restarts.
By the way, video card is ATI Radeon HD 5850, and processor is i5.
I got the video card about 2 years ago shortly after buying the new pc, and to go along with it I also bought a better power supply (old one 300w, new one 700W). The new video card said it recommends a PSU 500W or greater.

Anyway, I still had a hunch it might be the video card so I put my old video card back in, keeping the 700w power supply in. problem persisted.

Seeing that I don't get a blue screen of death or anything, i thought maybe the power supply is failing, so I put the old 300w power supply back in (with old video card in still). Old power supply was used for perhaps 2 months, so i know it's not bad. Problem still persists.

Ran memtest86 (burned memtest86 iso to a disk and booted from it) to check for errors in RAM. no errors were found.

This is as far as I've gotten.

The next thing I'm going to try is use only 1 stick of RAM at a time (i have 4 X 2gb each totaling 8gb) just to make sure it's not one of the sticks of ram that is the problem.

What else can i check for?

I would really appreciate any advice or suggestions. Thanks in advance!


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## linderman (May 20, 2005)

and aged 300 watt power supply isnt going to run anything; I would replace the power supply with a corsair 750

try running single stick memory; many times a failing power supply will kill the memory sticks

after that try a bootable CD like Ultimate Boot CD - Overview then unhook your hard drives from the system and run a stres test from within the bootable CD


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## Tyree (May 10, 2009)

PC Specs?
Prebuilt- Brand & Model Number.
Custom Build- Brand & Model of Mobo-CPU-Hdd-RAM-GPU-PSU.
650W minimum SeaSonic-XFX-Corsair (not the CX or GS Series) for the 5850.


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## jon_12156 (Aug 9, 2009)

Prebuilt Gateway DX4831-05 Intel Core i5 650 (3.20GHz) 8GB DDR3 NVIDIA GeForce G310

bought it 2 years ago
it came with a 300w power supply and the nvidia geforce G310
2 months later, i upgraded with a 700w OCZ Technology MODXSTREAM-PRO power supply and the ati radeon HD 5850. Is that a decent power supply?

To troubleshoot my problem, i put the stock hardware back in (again, which was only used for 2 months). It has been 2 days now and it has restarted once.

I ran a stress test called BurnInTest from passmark.com (just found that googling). The computer did not restart during the test and this test, in addition to memtest86, did not find any errors.

Still, as soon as it restarts again, I'm going to try running on only one stick of memory. And I will try the bootable cd stress test. Thanks.

if the specs i posted are not detailed enough, could you please let me know what you are looking for and perhaps a good program to use to get a printout of the specs?


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## Tyree (May 10, 2009)

Some OCZ PSU's are OK but none are top quality. If the PC is functionally normally with the old hardware that helps confirm you had a power problem. If you want to reinstall the 5850GPU I would suggest a good quality 650W minimum PSU as listed in Post $3.


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## linderman (May 20, 2005)

the ati 5850 takes one hellva power supply to run it; I dont see any mod stream 700 going to do that especially while gaming

but / run memtest (bootable version only) and ALWAYS test with only one stick of ram at a time ......run the test one hour per stick of memory


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## jon_12156 (Aug 9, 2009)

well, i've tried running each stick of ram by itself in the first ram slot in my pc. Already ran memtest86 on each of them, but this last one i'm using now. The computer has not restarted once unexpectedly while running on any single stick of ram, so it seems that the neither the power supply nor the video card are the problem. also, it seems that all the sticks of ram are good (no restarts while using any one of them alone).
Perhaps the problem with with one of the ram slots in my motherboard. Unless given a better suggestion, i am going to try running the current stick of ram in each of the 4 slots (after i memtest86 this stick.)
Is this a possible explanation for my problem? that one of the RAM slots is broken?


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## Tyree (May 10, 2009)

How many RAM sticks are being used to get the 8GB total?
Problems with 4GB sticks are not uncommon and filling all the RAM slots can cause Voltage problems.


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## jon_12156 (Aug 9, 2009)

4 x 2gb


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## linderman (May 20, 2005)

often times when running all 4 sticks populated you have to bump up the ram voltage .01 volts (i.e. increase from 1.5 to 1.6)

also try running OCCT (free download) let it run for 30 minutes ......monitor the temps and voltage fluctation from within the OCCT program; hopefully you will see some erratic readings just before a crash occurs


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## jon_12156 (Aug 9, 2009)

k, should i bother with my original suggestion of what to do next: 1 stick of ram only, test each slot?

or should i just put all the sticks in and run OCCT?
does it have any logging capability? I ask because I can't be there to monitor it 24/7. how long might it have erratic readings before it crashes, like half a second? or 5 minutes?


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## Tyree (May 10, 2009)

Try running 2 sticks and see how it goes. 4GB is plenty if you're not doing serious graphics or CAD work.


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## linderman (May 20, 2005)

no logging that I am aware of? when I run OCCT for this purpose I always monitor the readings personally for the 30 minute run


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## linderman (May 20, 2005)

Tyree said:


> Try running 2 sticks and see how it goes. 4GB is plenty if you're not doing serious graphics or CAD work.




excellent suggestion


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## jon_12156 (Aug 9, 2009)

ok yeah good idea. 2 sticks.

there are 4 slots of course, in order they go black, white, black, white.

I should put the 2 sticks in the black slots only, or the white slots only, right? 

not one in black, one in white. or in other words i should put them in slots 1 and 3, or 2 and 4, rather than 1,2 or 3,4.

this is so it can run in dual mode or something, right?


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## Tyree (May 10, 2009)

All Mobo's are not the same. "Usually", the slot nearest the CPU and 3rd from the CPU. 
Those being the two white slots on your Mobo from the pics I find.


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## jon_12156 (Aug 9, 2009)

oh, right you are! it is white, black, white, black (in order from closest to CPU). you found pictures, how resourceful. ok, I will try one in each of the white slots, and post back here later.


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