# Computer won't start after OC



## badger1337 (Apr 4, 2010)

Hi. 
I have overclocked my computer and now it won't start. I have asrock x58 extreme mobo, intel i7-920 cpu and a 750W psu. In the BIOS there were some preconfigured OC settings and I just picked one of these (3,6 Ghz). The computer was running fine for about 40 mins and 3dmark vantage was run without problems (cpu temp was 40 C). I then started a stress test with Prime95, then drove my brother to the train, and when I got back the computer had switched off. Only after removing the cmos battery and reseting the cmos with the jumper I can get any reaction when pressing the power button, but it's only for less than 1 second (fans and lights turn on for a short moment). I've tried disconnecting the cd-rom, 2 of 3 ram-blocks and the powercord to the mobo also when resetting the cmos (also waited 10-15 mins before putting jumper back to normal and replacing the battery) though it doesn't seem to do any difference. 

Anyone knows what to do?

-Martin


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## MonsterMiata (Jan 5, 2010)

System specs including psu


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## grimx133 (Jan 15, 2008)

Try another video card in it.


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## badger1337 (Apr 4, 2010)

System specs:

Mobo: ASRock X58 Deluxe
CPU: Core I7-920
Cooling: Noctua NH-U12P Special Edition 1366 (2 fans)
RAM: Corsair XMS3 3 x 2 GB
Graphics: Club 3D HD4890 Overclocked Edition (1 GB)
PSU: Corsair TX750W
HD: WD Caviar Black WD1001FALS 1 TB

Dunno if I should add that the Prime95 test says it "tests some of everything, lots of RAM tested" (test is called "Blend").


You would have to explain to me how another graphics card would change anything (since I don't have another at hand atm) :smile:


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## MonsterMiata (Jan 5, 2010)

Try clearing the cmos with the jumper.


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## grimx133 (Jan 15, 2008)

See if you can borrow one, the last time I saw the same thing happen, it was the video card. Came home, computer off. Clear cmos and just get a twitch, then nothing. Clear cmos again, every time all that would happen is one twitch, and just once, until cmos cleared again. Slapped in another video card, and booted up without issue.
Might be the same.


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## MonsterMiata (Jan 5, 2010)

grimx133 said:


> See if you can borrow one, the last time I saw the same thing happen, it was the video card. Came home, computer off. Clear cmos and just get a twitch, then nothing. Clear cmos again, every time all that would happen is one twitch, and just once, until cmos cleared again. Slapped in another video card, and booted up without issue.
> Might be the same.


Do these boards have onboard graphics? Bit different from what you said but its worth a shot if he has no other card. I can't find out if this board has onboard graphics or not.


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## greenbrucelee (Apr 24, 2007)

MonsterMiata said:


> Do these boards have onboard graphics? Bit different from what you said but its worth a shot if he has no other card. I can't find out if this board has onboard graphics or not.


No they don't have onboard but they do support quad sli so the GPU speed may have got screwed with the OC.

To the OP did you set the PCI-E frequency when you overclocked? if not you need to reset the cmos and reset back to default then reapply the OC settings with the PCI-e frequency set to 100.


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## badger1337 (Apr 4, 2010)

The PCI-E frequency was 100 before i changed anything at all, and still at 100 after i chose the preconfiguration


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## greenbrucelee (Apr 24, 2007)

you need to manually set it 100 even if it is set automatically to 100. This may or may not work but it stops any FSB increase tampering with the pci-e setting.


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## badger1337 (Apr 4, 2010)

In the bios OC-mode was set to 'manual' when I chose the preconfig and here the pci-e freq was set to 100. Anyway the computer cannot turn on atm so it doesn't matter ^^

Here's what I've tried so far:
Turning on the computer without graphics, then without ram, then without both of those, then without cpu (graphics and ram installed) then without all 3 of those. I tried removing the battery and clearing cmos 6-7 times now. I can still only get a splitsecond of life from it (fans start and stop immediatly) after I clear cmos or remove battery. Jumping the psu works fine.

Any ideas?


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## greenbrucelee (Apr 24, 2007)

borrow another psu.


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## badger1337 (Apr 4, 2010)

I just found an old psu in the house and tried connecting it to the mobo. All fans and lights stays on when I press the power button with this one connected. So I guess this solves the problem for now.

Thanks everyone


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## greenbrucelee (Apr 24, 2007)

make sure you buy a good make of psu, crap brands always cause problems and psu problems can cause errors that seem to be software or hardware related when they are infact not.

Good PSUs: Corsair, Seasonic, CWT, PC power and cooling, OCz extreme, Thermaltake toughpower units.

Power supplies to avoid: Anything made by Rosewill and huntkey, any generic psu.


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## badger1337 (Apr 4, 2010)

The psu I was using is a Corsair TX750. And I just found out that this still works when connected only with the atx wire (like I did with the old psu I found). I tried istalling the cpu, ram and graphics and the computer still turned on when I pressed the power button. Nothing happened on my screen though and I could not turn the computer off again (unless I pressed the switch on the psu) . Then I connected the 12V wire and now nothing happens again when I press the power button. Is it still certain to say that it's the psu that's the problem?


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## greenbrucelee (Apr 24, 2007)

could be the actual 12v which is dead, corsairs have a 3-5 year warranty.


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## badger1337 (Apr 4, 2010)

Okay. I can add that before I oc'd my com, when I turned on my computer one of the fans would go at full speed (really noisy) - I think it's the one on my hd 4890 - for about 1 second and then slow down again so you can't hear it. Now when I turn on my com (without the 12V wire connected) the noisy fan doesn't slow down, it just continues. And still nothing happens on my screen.

I also tried connecting the old 350W psu with both atx and 12V wires (only cpu, graphics and 1 ram block installed). Nothing happens when I press the power button in this case (same as with the corsair psu). Looks to me that it's the mobo that's the problem. What do you think?


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## greenbrucelee (Apr 24, 2007)

fans peeding up and slowing down usually point to an overheating or power problem.

If the fan was revving up to full speed and staying like that the deffo an overheating issue. If it was speeding up and slowing down then speeding up then slowing down that would equal power.

The only way to tell if your mobo is knackered is to bench test it with other hardware I am still guessing you have a psu issue as a 350w psu isn't good enough to run the system you have with the graphics card you have. you need a minimum 550w to run that card and thats before hard drives and anything else.

how to bench test http://www.techsupportforum.com/f15/how-to-bench-test-your-system-262998.html


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## badger1337 (Apr 4, 2010)

Okay. I though it was just a failsafe to ensure that the graphics card didn't overheat at startup since it didn't continue to go at full speed and rarely did when the com was being used (still talking about before the oc).
And then my guess of why it now continues to go at full speed was that the computer never actually does anything, but just powers on (some of) the hardware, since my screen stays black at all times (like the computer is powered off). I though that this might be possible if the mobo was malfunctioning in some way, but I have no idea really 

I wasn't sure that the 350W psu was powerful enough when I found it. I did a test online to find out what psu you need for your system and that test indicated that it might work with only cpu, 1 stick of ram and the graphics card connected. So I gave it a go. I will see if I can borrow a more powerful one. Thanks for the bench test link - I will try that if another psu doesn't change anything.


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## greenbrucelee (Apr 24, 2007)

I wasn't talking about the graphics card overheating I meant the cpu.

is the heatsink attached properly?


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## badger1337 (Apr 4, 2010)

Okay. I have verified that it is the graphics card's fan which is speeding up (and only that one). Everything is mounted correctly (triple checked everything). 
I have now tried a 520W psu with only cpu, 1 fan on heatsink, 1 stick of ram (tried with all 3 sticks separately) and graphics card (without any PSI-E cords attached). Still same result as with my own psu. I also got to test my psu in another pc and it works without any problems at all. So I think it's safe to say that it's not the psu  I will try bench testing the system soon.


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## Arcc4 (Aug 21, 2009)

I suggest checking closely for any blown or bulging capacitors especially around the CPU.


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