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Custom PC Randomly shuts down and will not power back on!!! HELP!

Last response: in Systems
January 13, 2011 2:49:48 PM

I was playing Starcraft 2 with high settings then one day my entire PC powered off! I tried pressing the power button but nothing happens. After about 10 minutes, my PC turns back on by its self???

I've been reading different forums with people who are having the same problem, and they suggested that it was SC2 not anything else. However, in my case, there have been a few times, since the initial power off, that my PC just turns off randomly. Sometimes it happens when just surfing the internet. I unplugged the power supply for about 5 minutes, then the PC was able to boot up.

Last night, I was playing SC 2 on high settings again, and it did it again! This time it wont turn back on? Even when I unplugged the PSU for 10 minutes?

I thought it might be an overheating problem with either the CPU/GPU, but I was monitoring those temps using RealTemp, Core Temp, and CPUZ-ID, but my CPU only got to about 52 deg on any of the cores and my GPU only maxed at around 62 deg??

When I have the PSU switched on, I can see the green LED on my mobo indicating that there is power to the board, but the damn thing will not power up!!

Here are my system specs:

CPU - Intel i7-950
Mobo - Asus Sabertooth x58
Memory - 6GB (3x2GB) Corsair Dominator DDR3-1600
PSU - Corsair TX750W (I read this may be the problem)
GPU - EVGA Nvidia GTX 460 Superclocked 1GB
HDD - 1TB WD caviar blue
SSD - 2 Intel X-25M 80GB
7 case fans - 6x120mm and 1x200mm
Antec 1200 case
HSF - Coolermaster Hyper 212+ with and additional 120mm fan.

I believe I've narrowed it down to either my PSU or my mobo, but I'm not sure how to tell exactly? Or is it something else?


January 13, 2011 3:45:17 PM

Sounds like your PSU blew out. Do you have a spare PSU (like one that could be borrowed from another computer) or a friend who would let you borrow his/her PSU to test on your system?
a b B Homebuilt system
January 13, 2011 3:47:31 PM

This to me would sound like your PSU is dead/dying. Not all parts of a PSU will die when they die so it may still be drawing some power but when your graphics card or other things kick in the system dies. I would try repalccing the GPU or RMAing it if it is still under warranty and getting a new/bigger psu. If you have another psu around you could try plugging that in and seeing if the computer runs minus your gpu. My ohter thought here is that their may be something wrong with the GPU and it is overheating and causing the system to shut off to protect it. As it has happened more than once more damaged is being done to the GPU. IF the computer will run without the GPU than you know that it is probably that.
Related resources
January 13, 2011 4:01:43 PM

Unfortunately, I do not have a spare PSU... So I'm forced to get a new one. I was suspecting that it was the PSU, but didn't know for sure.

Do you guys have any suggestions as to type and brand I should look in to? Obviously not going back to Corsiar PSU. But I heard Seasonic or coolermaster are top of heap? How about wattage, should I stick with the 750W or go higher?

As for the GPU, I really hope this is not the culprit, but I'll have to do more investigation when I get a new PSU...
January 13, 2011 4:05:07 PM

I actually thought Corsair was pretty top-line--anyways, don't they have 3 or 5 year warranties? You probably can RMA it!
January 13, 2011 4:34:37 PM

Cannot RMA it, I purchased it in October of last year :( 
January 13, 2011 5:41:56 PM


I just looked it up, your PSU has a 5 year warranty (see below), so if you bought it 3 months ago, it IS still covered. See the link below for the RMA process!

TX and VX Enthusiast Series™ (Models TX650, TX750, TX850, TX950, VX450, and VX550) have a 5 year warranty
- from Corsair's Warranty Info page

a b B Homebuilt system
January 13, 2011 6:21:30 PM

Most of the main stream companies hav 3-5 year warranties anymore. As long as there wasn't green or blue smoke coming from the box you should be ok with rmaing the old one and getting a new one from corsair.
a b B Homebuilt system
January 14, 2011 4:19:50 PM

if it's working it is probably overheating and you may have an under powered gpu. Also if you have taken anything apart that requires thermal paste did you put the small amount you should use back on to correct for taking something apart (this would be coolers and such for your gpu or other parts).
January 14, 2011 11:39:19 PM

I've been having a very similar problem, actually, so let me siphon off a little bit of the excellent advice you're getting, in the hopes that it will apply to you too.

CPU - Phenom II X4 925
Mobo - Biostar A770E3
Memory - amp DDR3 2x2Gb
PSU - Thermaltake TR2 600W
GPU - EVGA GeForce 9800GT

My shutdowns have been very similar to the OP's. They are extremely sporadic, spaced anywhere between 4 days or 15 minutes apart. Unplugging the power for 10 seconds always allows it to power on again. There seems to be very little correlation between system load and shutdowns, as it has happened while playing Mass Effect, while surfing the internet, and while simply loading Windows. I had assumed that there was something wrong with my CPU fan (using the cheap one that came with the CPU), but perhaps it's the PSU instead. Is there any way to check how hard the PSU is being pushed? My spare PSU only provides 430W. Would this be enough to power my system?
a b B Homebuilt system
January 14, 2011 11:48:03 PM

yeah this probably means you could use a larger power supply (think I typed gpu twice in the last post I made) or your card is over heating. Not sure how the EVGA psu stacks up to others, but that should be one the low but doable end for your computer sageth, I like to leave 15-20 percent clearance at least because most calculators are not always taking into account the ammount of power you will need at full load and I like to stay under the 80-85 perecent range of full compacity just to be safe.
January 15, 2011 1:03:44 AM

The PSU is Thermaltake, not EVGA. Do you mean to say that 600W is not enough to handle the GPU?

And let me also reiterate my other question: Is there any way to gauge how hard my PSU is being taxed? It doesn't seem to be particularly hot (to the touch) when it shuts down, as I would expect an overloaded PSU to be.
January 15, 2011 1:41:06 AM

You could plug a watt meter in, between the wall socket and your PSU, I suppose? You can borrow them from most public libraries, surprisingly...
January 15, 2011 1:48:11 PM

Called around, and none of the nearby libraries have one. I suppose I could just buy one, and return it when I'm done with it.

Could I perhaps decrease the voltage sent to my CPU, below the default, and see if that stops the shutdowns? Sort of an inverse overclock?
January 15, 2011 3:57:38 PM

Hmm, you can monitor the voltages in the BIOS, so I imagine that there must be some program you can run that will monitor and/or log your voltages while you're using your computer, so you can see what they were at when your PC shuts-down--maybe someone else who knows more can fill-in here?
a c 122 B Homebuilt system
January 16, 2011 4:01:53 PM

Work systematically through our standard checklist and troubleshooting thread:
I mean work through, not just read over it. We spent a lot of time on this. It should find most of the problems.

If not, continue.

I have tested the following beep patterns on Gigabyte, eVGA, and ECS motherboards. Other BIOS' may be different, but they all use a single short beep for a successful POST.

Breadboard - that will help isolate any kind of case problem you might have.

Breadboard with just motherboard, CPU & HSF, case speaker, and PSU.

Make sure you plug the CPU power cable in. The system will not boot without it.

I always breadboard a new build. It takes only a few minutes, and you know you are putting good parts in the case once you are finished.

You can turn on the PC by momentarily shorting the two pins that the case power switch goes to. You should hear a series of long, single beeps indicating memory problems. Silence indicates a problem with (in most likely order) the PSU, motherboard, or CPU. Remember, at this time, you do not have a graphics card installed so the load on your PSU will be reduced.

If no beeps:
Running fans and drives and motherboard LED's do not necessarily indicate a good PSU. In the absence of a single short beep, they also do not indicate that the system is booting.

At this point, you can sort of check the PSU. Try to borrow a known good PSU of around 550 - 600 watts. That will power just about any system with a single GPU. If you cannot do that, use a DMM to measure the voltages. Measure between the colored wires and either chassis ground or the black wires. Yellow wires should be 12 volts. Red wires: +5 volts, orange wires: +3.3 volts, blue wire : -12 volts, violet wire: 5 volts always on. Tolerances are +/- 5% except for the -12 volts which is +/- 10%.

The gray wire is really important. It should go from 0 to +5 volts when you turn the PSU on with the case switch. CPU needs this signal to boot.

You can turn on the PSU by completely disconnecting the PSU and using a paperclip or jumper wire to short the green wire to one of the neighboring black wires.

A way that might be easier is to use the main power plug. Working from the back of the plug where the wires come out, use a bare paperclip to short between the green wire and one of the neighboring black wires. That will do the same thing with an installed PSU. It is also an easy way to bypass a questionable case power switch.

This checks the PSU under no load conditions, so it is not completely reliable. But if it can not pass this, it is dead. Then repeat the checks with the PSU plugged into the computer to put a load on the PSU.

If the system beeps:
If it looks like the PSU is good, install a memory stick. Boot. Beep pattern should change to one long and several short beeps indicating a missing graphics card.

Silence, long single beeps, or series of short beeps indicate a problem with the memory. If you get short beeps verify that the memory is in the appropriate motherboard slots.

Insert the video card and connect any necessary PCIe power connectors. Boot. At this point, the system should POST successfully (a single short beep). Notice that you do not need keyboard, mouse, monitor, or drives to successfully POST.
At this point, if the system doesn't work, it's either the video card or an inadequate PSU. Or rarely - the motherboard's PCIe interface.

Now start connecting the rest of the devices starting with the monitor, then keyboard and mouse, then the rest of the devices, testing after each step. It's possible that you can pass the POST with a defective video card. The POST routines can only check the video interface. It cannot check the internal parts of the video card.
January 16, 2011 9:00:10 PM

I appreciate the obvious effort you guys have put into this, but the above seems only to apply to people who are having issues booting up. I have no issues booting up. My computer works perfectly for days at a time. I am currently logging all voltage on my computer, and am waiting for a shutdown so that I can post the logs. I guess my PSU realized it was being logged, and got stage-fright. :p 

Is there something in there that applies to my situation, that I may have missed?
January 17, 2011 2:43:14 AM

Haha, nice--what program are you using to monitor and log your voltages?
January 17, 2011 3:06:36 AM

I'm using SpeedFan, a utility I found on CNET. Honestly, I'm not sure what to be looking for, voltage-wise. I'm reading +4.95 under the +5V header, 12.03 under the +12V header, etc. If the PSU is borked, should I expect to see a spike or dip in value right before the computer shuts down?
January 17, 2011 4:12:12 AM

Small variations are pretty normal (if you read reviews of PSUs, this is one of the things they test for, so looking up reviews for yours might give you an idea of the expected variations).
a b B Homebuilt system
January 17, 2011 2:40:08 PM

sargeth said:
The PSU is Thermaltake, not EVGA. Do you mean to say that 600W is not enough to handle the GPU?

And let me also reiterate my other question: Is there any way to gauge how hard my PSU is being taxed? It doesn't seem to be particularly hot (to the touch) when it shuts down, as I would expect an overloaded PSU to be.

Sorry I didn't get back to this sooner, What i was trying to say in my last post Sargeth is that 600w on paper should be ok, but at load wiht multiple things running it is probably on the low end of ok in terms of power consumption. Also my mistake I read the gpu type not the spsu type when I wrote my last post (I was thinking that seemed odd when I typed it too, but it happens). I am not sure how much power all your components pull at load, but as a psu ages it will also not run at peak preformance which is why I like to give it some top end clearance too. If your computer and power supply run all the time this will probably age the parts faster, as will running at the higher end of its compacity (say using 100% of what it can pull as opposed to the 30-80 percent when you get peak efficienty from the power supply). I have bought some very nice (and relatively cheap for their size at the time) power supplies from .
January 17, 2011 4:01:07 PM

Ah, thanks for getting back to me on that, evilavatar. I think the Newegg PSU calculator put my system around the 500W mark, so I thought 600W was leaving plenty of headroom. What calculator are you using?

I finally had a series of shut-downs, one after the other, and I'm afraid my logs displayed no sudden spikes or drops in voltage at any point. I think I'll just buy a new PSU from the local Best Buy, run on it for a few days, and if it seems to fix my problem, I'll RMA this one and return the Best Buy one.
a b B Homebuilt system
January 17, 2011 5:23:45 PM

running a 600 watt PS at 500 watt load is not really 'plenty of headroom'.....; much better to have 200 watts to spare, IMO....
a b B Homebuilt system
January 17, 2011 5:24:52 PM

well the problem with any of the calculators is they may not take full load at the high performance end when gaming, even thought the 9800 does not use that much power per se. I actually try to do all the math on paper and count all the items so I get it right than check 2-3 calculators and see what they give me. New eggs seems decent but there is always some variation between the calcualtors (I have seen 50-150 watts on what I am doing with my own computer). Overclocking the video card and/or chipset will draw more power and most of the system calculators will take into account overclocking your mobo but not the video card.
both of these are good as well.

you also should specify is you are overclocking as the calculators need to add more wattage for this as well.
January 18, 2011 1:01:32 AM

No, not overclocking. If I can't get a computer to work on default settings, overclocking would seem simply foolhardy.

I picked up another PSU today, and set it all up. This is a modular Thermaltake TR2 RX 850W. I am still having problems.

The shutdowns, while equally frequent and sporadic, are different than before, however. Before, all power to the computer was cut off and I had to unplug the power supply. Now, the monitor and speakers lose signal, but the fans and HDD continue to whirr. I am able to start the machine back up by resetting; no unplugging of the PSU is required.

January 23, 2011 1:29:50 AM

It's been a while since I last posted about this, but I got an update on my system.

Turns out that I didn't need a new GPU, PSU, or anything else!

What I did was I took my GPU completely out, sprayed the inside of my PC with compressed air, which particular attention to the PCI-E slots, and put my GPU into the second card slot on my mobo.

Secondly, I uninstalled/reinstalled all the drivers for the GPU.

Now I don't know which one did the trick, but my system has yet to see a random shutdown in days!!! =D

I kept researching about this topic on other forums, and it seems to be a overheating issue (thanks eilavatar!) with the GPU.

Before while playing DC universe, I saw my GPU temps reach 50-52 deg C, now it doesn't get hotter than 45! =)

I'm also using EVGA Precision tool to monitor the temps while gaming.

One more thing, I also forced VSYNC always on, on my nvidia control panel, I read somewhere that this will help to limit the frame rate on game, so they wont overload/overheat the GPU.
January 23, 2011 3:35:22 AM

Congrats--that's terrific! Thanks for coming back to post what finally worked--hopefully it will also help other poor gamers whose computer was having the same issue as yours.