I pulled another Corsair CX430 from inventory, tried it, and got the same rebooting behavior.
During a long chat session with Intel support it occurred to me to install Intel’s Desktop Utility that measures fan speed and voltages. IDU immediately began warning me that the +3.3V supply was too low (3.080V). We decided it must be the NIC circuitry (after trying several different NIC driver versions) and assumed that the Corsair CX4320 PSU must be incompatible with the DQ67SW, or at least the +3.3V supply is marginal.
Wow, thank you for posting such an extensive descriptions of the problems you've encountered!
I feel I'm suffering from the same problems!
- i7-2600k CPU
- SSD - tried both an Intel 160GB Postville and the OCZ Vertex 3
- Seasonic S12II-430Bronze PSU (which has always worked perfectly in the old Core i5-661 System)
- some Ram (which has always worked perfectly in the old Core i5-661 System)
intermittently and completely unexpectedly reboots. But it's not a bluescreen reboot (I switched that off the very first time it happened to be sure thats not the case) and it "feels" more like powering down for a second and then going back on when I catch the system doing this.
It's definitely not cpu-load or heat related, if anything it seems to happen more when the PC is idling then when it's actually in use.
Sometimes it happens twice in an hour, sometimes it takes 6 hours until it happens. But it's definitely not working at all like it's supposed to be and is very very frustrating...
I've switched the SSDs between the Intel and the OCZ, which didn't change anything. I'm also using GBIT Ethernet, have not yet tried if going back down to 100MBit makes a difference. It may very well be that the problems only occur on my system with no HDD connected because during the initial installation I did not have problems - and I also had my Backup HDD connected at the time...
I'm really wondering that to do now, throw the board in the trash and get a DH67BL? Buy and try other PSUs until I find one that accidently works?
RMA the board ? (I'll probably get another one that's just the same)...
(a slightly frustrated) anybody (who is nevertheless incredibly grateful for your post here)
PS: My voltages in the IDU utility look fine though. Perhaps they only drop just before the reboot? And those seem to be way more sporadic than in your case!
"this thread" doesn't in any way reveal what option this is supposed to be. I've searched the entire BIOS and was unable to find anything that even sounded similar.
"Connect a traditional HDD to the system and see if the rebooting problem goes away."
I have since bought a new power supply to test if swapping the power supply to something completely different (different brand, 2 years newer than the one I was using before) makes any difference: It did not. After not-switching-off for 2 days (on the old Seasonic S12II power supply) the computer did it again this morning. I immediately switched to the new PSU (be quiet! Straight Power E8 500W), and only a short time later it happened again.
PSU did not make a difference in my case.
I then connected a trusty WD Raptor 36GB SATA "traditional HDD" to my system. This HDD was active the entire time, it did not go into sleep mode, and it was in use. And the "switch off => switch on" happened again within quite a short time.
So, basically I did everything I could to eliminate the "problem" and it's still here. I've now loaded the Standard BIOS settings. While I had not changed anything of importance, perhaps some stupid thing like me disabling firewire or serial ports causes the problem? I'm now running the BIOS with 100% default settings except "Numlock OFF". I'll report back if the problem persists (which I would expect).
UPDATE: It has powercycled again. BIOS defaults didn't help. I will try to exchange the Q67 Board on monday. If I won't get a direct replacement for it I'll buy a DH67BL and RMA the Q67.
Since I can't buy a replacement board for the weekend I'll also try if limiting Ethernet to 100MBit helps, but i'm not too optimistic about it.
UPDATE2: 100MBit/s didn't make a difference.
UPDATE3: Several months later it is still unclear what caused my problems. I had then changed motherboard to the DH67BL and just kept the DQ67SW around. Never ever had those reboot/powercycle problems any more. Then, 1-2 months later I had to build a PC for someone... I used the DQ67SW and tested it for some time before giving him the PC - it worked fine. And this PC is running the new location almost 24/7 with the DQ67SW in it and I've never heard any complaints at all. So basically my problems went away after exchanging the motherboard for something else, yet the motherboard in another system works fine too. Yet, with all my troubleshooting and component-exchanging, I was never able to get it to work in MY system (and i really changed EVERYTHING). Nothing really makes any sense here - but the problem is gone without really being solved.
Might be a long shot, but try double checking that the heatsink/fan assembly is really snapped into the motherboard. I was seeing random reboots with a i7-2600K that resisted all HW swap attempts, until I realized that not all 4 plastic HSF tabs were completely locked in place behind the motherboard. Fortunately it seems I avoided any long term damage to the CPU.
Here is Intel's reply: