Random reboots without BSOD

[MalachiMulligan]

Hi,

I recently bought a new system and have been experiencing random reboots. They happen without any identifiable pattern - could be days without a reboot, could be several within an hour. There are no Blue screens or error messages ( I have the restart on error option in Windows turned off). There are also nothing in the Event logs what would seem related to the reboots.

Here are the system specs:

CPU: Core i7 2600K
MB: GigaByte GA Z68X UD3H B3 (rev 1.0) with F4 BIOS update
Memory: 2X Kingston KHX1600C9D3/4G
HDD : 2X SEA Barracuda.12 1TB in raid1 on the intel controller (I disabled the Marvell controller while troubleshooting)
PSU: Chieftec 600W CFT 600 14CS

OS: Windows 7 64bit

What I've done so far:
1. Reinstalled Windows - the reboots happen without any additional software installed.
2. Started monitoring the temperatures with SpeedFan - Under normal load the temperatures on all the sensors never exceed 40C
3. run memtest on the memory - no errors
4. run Prime95 for about 6h - the temperatures didn't exceed 70C and no reboots during this time.
5. tried running the system of only one hdd at a time - reboots happened with both of them.
6. assembled the system outside the case with no restart or power switches attached to exclude something shorting out - the reboots still happened.
7. tried running it without a ups (Fortron Line Interactive UPS EP-2000, 2000VA, 1400W) - the reboots still happen

I earn my living at online poker - so any reboot is not just irritating but costing me actual real $$$. That's why I have the UPS and RAID in the first place

Any advice on what else to check / next steps would be greatly appreciated.

 

[stargazr]

Did you do any searches in the motherboard forum? There are several threads devoted to Z68 issues.

 

[Harvey]

It could be a faulty power supply or one that's marginally sufficient for most operations. Did you try unplugging and re-inserting your video card?

Also, check the capacitors on the motherboard and the vid card. If the tops of any them are domed, instead of flat, or if there's any sign of leakage around the base, they're shot.

 

[MalachiMulligan]

If the capacitors are the barrel like things all over the motherboard, then I checked them and all seem to be OK. There are a few below the CPU cooler which I can't really see though.

I don't have a separate video card. I run 2 monitors off the built in graphics.

As for the PSU. I thought that 600W should be sufficient if I don't use an separate video card. I don't know if it's a good idea, but I could try to replace it for testing with a 500W Codegen I have lying around althou it only has a 4 pin CPU connector.

In the meantime I also have tried all the BIOS settings which I could find in the motherboard forum (Like disabling USB storage function and the various power saving options) and it hasn't rebooted for about 24h, but I have had the reboots after it's been up for longer, so it's hard to tell if the problem has been fixed.

Anyway, thank's for the suggestions.

 

[BoomerD]

It looks like the Chieftec PSU is CWT built. Perhaps not the best available, but SHOULD be up to the task.

The Codegen PSU...toss it in the trash...it's most likely a Powmax built unit...and not something to even consider.

I'd recommend pulling the board out of the case and seeing if it will run. Your problem can often be caused by grounding issues...maybe a stand-off in the wrong place?

 

[Saithegeek]

It looks like the Chieftec PSU is CWT built. Perhaps not the best available, but SHOULD be up to the task.

The Codegen PSU...toss it in the trash...it's most likely a Powmax built unit...and not something to even consider.

I'd recommend pulling the board out of the case and seeing if it will run. Your problem can often be caused by grounding issues...maybe a stand-off in the wrong place?

I agree with this user if your rigs a clone box made by Johnny down the street. Just can't trust basement builders. If it's from a store, take it back! Never pay for garbage with your hard earned money.

 

[BoomerD]

I agree with this user if your rigs a clone box made by Johnny down the street. Just can't trust basement builders. If it's from a store, take it back! Never pay for garbage with your hard earned money.

True dat...the OP doesn't say where the computer came from, or who built it.
If it's a "store bought" and he hasn't done any "modifications," then by all means, deal with the store, manufacturer. (warranty issue)

 

[denis280]

Did you do any searches in the motherboard forum? There are several threads devoted to Z68 issues.

Yes i do agree with stargazr there is some issue with those MOBO my opinion if its from the store bring it back.

 

[MalachiMulligan]

Just wanted to say, that the problem seems to be fixed.

After digging thru the motherboard forums I found the Ctrl + F1 trick, which allowed me access to the settings about which I had read, but couldn't find in my BIOS and just assumed that they didn't apply to my Motherboard. So after pressing Ctrl + F1 while in the BIOS and disabling

* CPU Enhanced halt (C1E)
* C3/C6 State
* CPU EIST

the computer didn't reboot for 48 hours, which gave enough confidence to start working on it again and all has been good for another 24h. I don't really have enough time or patience to enable the features one by one to see which fixed it, but just thought I put it out here in case it helps somebody else.

Cheers and thanks for your help.