Hello! Thank you for reading. I have been having trouble with my PC for months, I have tried many solutions but nothing works. This is a system I chose myself and then built in 2010.

My PC (April 2010 unless noted)

OS: Win7 Ultimate 64-bit
GFX: 2x over SLI EVGA 896-P3-1255-AR GTX260 Core 216 896MB DDR3 PCI-Express 2.0
Case: Antec Twelve Hundred
PSU#1: Corsair HX850w
PSU#2: Corsair HX620w (procured for troubleshooting in ~2011)
CPU: Intel Core i7-920 Bloomfield 2.66GHz LGA 1366 130W Quad-Core
CPU Cooler: THERMALRIGHT U120E-1366-RT U120E
       
CPU HS compound: Arctic Silver 5
MOBO: EVGA x58 SLI 132-BL-E758
RAM: 3 x 2GB G.SKILL PI Series 240-Pin DDR3 SDRAM DDR3 1600 (PC3 12800)
Timing 7-8-7-24-2N; Cas Latency 7;  Voltage 1.5V
HD: 1x WD Black WD1001FALS 1TB 7200 RPM 32MB Cache SATA 3.0Gb/s
 
I should mention that this system is not being overclocked. I haven’t done anything in the BIOS settings, everything is default, except for when I had to mess with boot order to use my usb memtest stick.

The two problems

Issue 1 on off on

When I turn on the computer, it begins booting for a few seconds, shuts down, then turns back on a moment later. It does this nearly every time I start the computer. I have managed to start it directly up only once, but that was with no GFX card.

This above link is an evga support page describing the automatic configuration cycle that the x58 chipset does. That cycle shows a F3,F6,F3,F6,etc on the AWARD post readout before shutting off. I have seen my PC do that after I’ve changed some hardware, and I figure that this is normal operation.
When Issue 1 is taking place, the post code shows F3, then solid F6 for a few seconds before shutdown.

Issue 2 post-boot shutdown

The computer just shuts off. After shutting off, the system turns itself back on again between three seconds and three minutes later and tries to boot again. This problem began happening as rarely as once a week and now it can happen only a few minutes after the computer boots into windows, and sometimes it won’t even make it to windows. Most of my testing was using PSU#2, the HX620w, until the system reached a point where it refused to power on at all, and I feared that the system was a doorstop. Then using PSU#1 again, the HX850w, I turned on the system, and it began to flicker on and off, each time staying on a fraction of a second longer, until it finally made it all the way to windows.

History

I have been dealing with this problem for months. In 2010 I thought nothing of Issue 1. Issue 2 began happening in summer of 2013 which is when I started trying to troubleshoot it. The computer would shut down with greater and greater frequency, sometimes when playing world of warcraft, sometimes without any stressful programs running at all. Finally the pc refused to boot at all. I found a scorch mark on the motherboard to the right of the power button (picture XX) and had to RMA the motherboard. Unfortunately the new board did not fix the problem.
Switching PSUs
I have tried switching out the PSU for a corsair HX620w. They are the same brand, but both PSUs received good marks at various review sites and they appear to be from different manufacturers, the 850 being from Channel Well and the 620 I think being Seasonic. Issue 1 and 2 continue to happen with both PSUs. Once after shutting down the system voluntarily, the computer simply does not boot with the PSU#2. When plugged in, the blue LED indicating power on the motherboard is on, but the PC is otherwise lifeless.
Switching GFX cards
Running only one GFX card at a time does not fix the problem. I numbered the graphics cards and experienced the problem with both of them. I have not had a spare, known stable GFX card to try with it yet.
Running Memtest+
I prepared my USB stick to boot with memtest, and made four successful passes on a single stick. This was before I was numbering the sticks, but Issue #2 continued to happen with that same stick of memory, in that same slot.
Using prime95
I tried using prime95 as a way to reproduce the shutdown problem on command. Running prime95 on torture mode in the blend setting causes issue 2 in under five minutes. I have not run prime95 more than twice because I don’t really understand how it works and I am afraid to damage my components. I’m not sure if prime95 is supposed to only stop stressing the system, or if it is really normal for prime95 to cause a complete computer shutdown.
Loosening the heatsink
The aftermarket coolers I read can be too tight on the CPU causing such problems. I’ve tested it loosened, and also with the heatsink simply resting on the CPU. Did not help.
Eleet overclocker software
I have installed this program to monitor temperatures and other variables, but I am not sure how to interpret the results.
Updating the BIOS
The original motherboard was using the original BIOS from the factory. The replacement board was already updated to version 83, which is the latest for this board on the x58 website. I have seen the issues on both boards.
 
In conclusion if you have any advice or suggestions please help. Thank you for reading this long post! If there is any information missing let me know, I will be watching the thread.

Thread update 2
I have researched how to enter ram timings and I will do this now. It has auto configured my ram at 7 7 7 20 1T. I am going to change it to 7-8-7-24-2N as my ram asks for. Done, except my bios does not have option for 2N command rate, only 1t or 2t. I left it at auto 1t. Computer shut down, restarted and is in windows at 2:29 pm. E-leet reflects the settings I have chosen.
 
2n and 2T seem to be interchangeable and 2T seems to be the safer setting, and I am changing it to 2T. Computer booted successfully with 2T. Shut down to try a cold boot. Started right up with no problem. Ostensibly fixed Issue #1….! No idea why the memory id chip did not automatically enter the values listed on the memory. Computer has now been booted three times without issue #1 and I have been unable to make it shutdown as with Issue #2. I will reply again if there is more trouble.

i have the same issues on my x58-i7920 box, which began in the summer 2013, and so far, based on searching around:
-many reports of these issues related to wow-nvidia and directx11 combinations
-some reports of solutions by disabling nvidia and other conflicting audio devices from device manager.
 
 

marshallm
Update:  I’ve managed to boot up my PC in a configuration that ran prime95 for seven hours with no errors and no shutdowns.

What PSU were you using when you ran this test? Are you still running that PSU on thread post #6? If so, it sounds like issue #2 is related to the motherboard.

marshallm

Sajin

marshallm
Update:  I’ve managed to boot up my PC in a configuration that ran prime95 for seven hours with no errors and no shutdowns.

What PSU were you using when you ran this test? Are you still running that PSU on thread post #6? If so, it sounds like issue #2 is related to the motherboard.

Thank you for your help! The PSU was #1, the HX850w. But I don't understand how it could be the motherboard. This is the RMA board, the replacement, and issue #2 was present on both the old board and this new one. Are you saying they could both be bad?

Yes, I am saying they are both bad. How old is the HX850?

You need to setup your ram with the ram timings on the stick, don't go back to auto or use the xmp profiles. The 2T or 2N is much more reliable than 1t or 1N, so use 2T. The N stands for AMD and the T stands for Intel in the command rate setting, but there really interchangeable, but theres no harm in using the appropriate setting for your build...so if its a amd build go ahead and use the 2N setting and if its Intel use 2T. You also need to manually configure your cpu vcore cause auto is horrible at sensing it correctly for stability. it might get you booted but it will be no where near stable.

wmmills: I have found the intel specs page for my CPU here:
It says that the correct voltage range for my processor is 0.800V-1.375V. If I change the vcore to a manual setting, what should I set it to for maximum stability?