Random rig shut down then power back on automatically

**Amoun** · May 8th, 2010, 09:41 PM

Hey everyone.
I am having a problem with my build.

Here is the build info:
i7 920 cpu
Asus P6T6 WS motherboard
Asus Matrix GTX 285 x2
2G Corsair DDR3 1600 RAM x3
Cooler Master real power pro 1000w power supply

PSU Voltages:
CPU Voltage: 1.232 - 1.224
3.3v 3.296
5v 5.046
12v 12.081 - 12.137 < got this when i switched the wire to an 8pin VS a 4 pin.

CPU idle tempt: 42.5
MB temp: 40-39

The problem:
When I game (and only game, I can do anything else and there are no problem at all) the computer would shut off and I do not mean just restart, BSOD or freeze but I actually mean the whole thing powers down, including the fans, and then turns back on.
The strange thing is, it does the exact same thing once I change the FREQUENCY of the RAM setting in my BIOS and click F10 to save and exit, and ONLY the frequency (the MB is rated for 1333 ram but I am using 1600 because it is on the approved vendor list, i actually got the exact model number right off it). I can change just about anything else in bios and the whole rig won't power down and then reboot. I tried playing with timings as well as setting the profile to XMP (it does the timings, voltage for me automatically etc etc).

I ran a memtest on each stick separately, each did 3-4 passes with 0 errors. I thought it might have been the video card (which is odd as I would imagine a BSOD would popup) but I have 2 (i took one out for now) and both have the same problem.

There is a video below so you can actually see what happens.
I have spent a long time trying to narrow down the problem but I just have no idea anymore.

YouTube - Computer fail

(p.s. yea the wiring is a mess and I'm sorry bout it I just keep taking it apart and putting it together so I did not fix the wiring yet)

**Atomic Rooster** · May 8th, 2010, 10:07 PM

Have you tried swapping out the power supply? It may be having a problem with the extra power draw while gaming. Not saying it's underpowered, it may have an internal problem.

**Amoun** · May 9th, 2010, 12:24 PM

Unfortunately no =\
I will still ask some friends around but I have a feeling they won't have it.

The worst case scenario is I can just buy one and return it if that's not the case.....just dont want to pay a 15% "restocking fee" on a $300+ PSU you know lol
The only think I that makes me IFFY about it being a PSU is that, as I mentioned, the EXACT SAME thing happens when I change the frequency. I asked ASUS about this because I had a feeling its a MOBO but they said it is normal for a system to restart and then turn back on after...even when I mentioned that everything powers down, including the fans.

**Qabouter** · May 11th, 2010, 10:17 AM

Hello,
I don't know for sure, but in your bios you should be able to set the power management for cases of loss of power. There are basically two options, either, in case of power loss, stay turned off afterwards, or when the power returns restart the PC.

Check in your BIOS whether it was set to restart after power loss, and set it to stay turned off in case of loss of power.

Then force the error again and see if the PC stays turned off. If the PC powers down and then automatically powers up again, it is less likely to be a PSU error, but something in your other hardware causing a crash.

If it powers down and stays off, then it's a power issue, since the BIOS detects loss of power and reacts to it by staying turned off. Then there are two possibilities. Either your PSU is faulty, causing a loss of power in higher demand situations, causing a power loss to your MoBo, and thus causing BIOS to detect loss of power and react to it. Either by shutting down, or resetting, whatever you set as option.

THe other possibility is that your PSU is fine, but your fusebox cannot take it. I don't know what kind of amperage fusing your home has, nor how much power other applyances in your house draw, that are connected to the same fuse-group as your PC. It is in principle possible with a 1000 W PSU in SLI mode on heavy gaming, together with some other applyances, that your fuse is overloaded. In modern fuse-boxes, to prevent short-circuit, the fuse is temporarily disconnected, and gets connected again after a second or so, to test if the overloading lasts. If the overload still lasts the fuse will blow after all.

Most household applyances won't notice a thing, because they have capacitors in them, keeping a stable power-supply for a few seconds after loss of electricity. Your PC in high-gaming mode, with a 1000W PSU (probably drawing around 500-700W I suspect) the PC will not last long enough to bridge the power-gap and thus will shut down. THe fuse reconnects and the overload had passed, so the rest of the house won't even notice the short power-glitch, but your PC does.

It is just a theory, which you might test by turning off, or changing the plug for a high-consuming applyance and then try forcing the error on your PC. If it then still fails, the best bet is a faulty PSU. AS said before it will not be an underpowered PSU. Your PC should run fine with a 750W PSU IMO.

**Axxis123** · February 8th, 2011, 03:57 PM

Sorry to dig up an old thread but I'm having this exact problem, OP says he fixed it with a new PSU but I'm not 100% sure if that would fix it for me.

When I first had this problem I was using an AITO 850w PSU, I sent the PC to a local computer repair man and he put in a brand new AITO 850w and it happened almost immediatly.. This PSU already has problems booting up the PC unless the power has been switched off for a while beforehand, so if I replace this PSU with a good quality one (Thinking Antec HCP-850w) will it surely fix my problem or could it still be another issue despite the video in OP being exactly whats happening to me?

Thanks for any help.

**JPMiller** · February 8th, 2011, 06:37 PM

First of all its highly unlikely you need anywhere near 800W in the first place, but without your specs, we dont know...
Use Speccy to give us a basic list of all your components...

**Axxis123** · February 8th, 2011, 09:06 PM

Originally Posted by JPMiller

First of all its highly unlikely you need anywhere near 800W in the first place, but without your specs, we dont know...
Use Speccy to give us a basic list of all your components...

I'm sorry, I should've included more information to begin with, using Speccy here are the specs:

Windows 7 64-bit
Intel Core i7 920 @2.67GHz
6.0GB Triple-Channel DDR3 @534MHz (Planning to add more RAM soon)
ASUSTeK P6T with Intel X58 Chipset
ATI Radeon HD 4800 Series (Planning to replace with Radeon HD 6870 soon)
1TB Western Digital WDC ATA Hard Drive
It doesn't mention the Power Supply in Speccy but as far as I've been told it's an AITO 850w.

Edit: It might also be helpful to know that I run two 1680x1050 monitors with the computer, I have tried only using one and the power loss still occurred. Also I added the somethings I plan to replace to help determine whether or not I need a 850w PSU.

**Gobgava** · February 19th, 2011, 03:29 PM

I have the same problem. Computer will randomly shut off and then after a few minutes, it will turn on. I am unable to turn the computer on manually after it shuts off. I have to wait until it decides to turn on again. I have a p6t6 ws revolution also with an i7 920, 2 gtx 260 video cards, a 1000w tpq antec power supply.