Win7 x64 crashing, no bsod or memory dump written

[merk]

I have a Win7 install - clean install, about 6-7 months old. Only being used for work purposes (web development) no gaming anything like that.

Randomly, as far as i can tell, my computer crashes. There's no bluescreen, no error log. The only thing to indicate something happened is that fact that everything I had open is closed and if i look in the event log there's an error 'previous system shutdown was unexpected' and a critical 'the system has rebooted without cleanly shutting down first...'

I ran the perfmon report and the only thing odd in there is it says there's no virus protection even though i have MS sec essentials running with real time virus protection turned on and virus def's are up to date. Although i see there's a hotfix available for this so i guess this is a known glitch in the report.

This has never happened while I am using the PC which is really strange. It usually only happened when I left the PC on over night. It just crashed now while I was out to lunch. It just seems very strange that it only happens when the pc is sitting idle.

I also ran the online virus scanner from trend micro a few weeks back while this was happening and it found nothing.

I have system recovery set to write a kernel memory dump - there's no memory dump file when this happens.

Since this sort of feels like the power is going out since there's no log written and no BSOD, I thought this might be due to a bad PSU, so i swapped that out for a new one to no effect. I also have a UPS (CyberPower CP600LCD) hooked up to the computer so this shouldn't be due to any temporary power glitches. Even if the power does go out the UPS should cleanly turn off the PC. I tested this by pulling the power chord from the wall and the PC shut down after a minute. The monitoring software from the UPS shows nothing wrong with the UPS.

Right now the only thing i can think of is something malicious/funky is running or the UPS itself is bad and glitching out. It just seems very strange that this has never once happened while I'm actually using the PC but only when it's been sitting idle. The only thing I have installed which usually runs while it's idle is mozy backup (aside from whatever typical window's processes run in the background). And that's only backing up about 300meg worth of files, most of which don't change.

Anyone have any ideas?

Win7 x64
16gb ram
120meg ssd
mobo GA-Z77-D3H
psu 500w (not sure of the brand)
nvidia gt 630
latest windows updates installed

 

[denis280]

Mobo and psu?? what kind and brand

 

[merk]

I updated the original message with the mobo and psu (i dont know the brand of the psu - i'll have to pop open the case later and look at it)

 

[Bubbaleone]

In Startup and Recovery; if you have "Automatically restart" unchecked, and "Write an event to the system log" is checked, then your machine shouldn't be restarting on it's own and not writing any event either. This behavior might indicate a hardware problem like the CPU overheating or a stick of bad RAM, rather than a malicious process. Although, because of the way they hook the API, certain boot sector viruses and rootkits are fully capable of shutting down a machine without Windows having a clue as to what just happened.

 

[Steltek]

What brand SSD do you have, and does it have the most recent available firmware installed on it?

Also, is your machine set up to go to sleep after a fixed amount of time with no activity? If so, try disabling sleep in power management for a while to see if it could be a glitch related to this.

I think it would also be a good idea to download and burn a Memtest86+ ISO and run your DRAM through a few test sessions on each memory module separately as a bad memory module can have all kinds of weird side effects.

 

[merk]

Dont know the brand of the ssd off the top of my head but i'll check when i get in the office tomorrow.

It's only set to turn off the monitors after a few minutes.

I dont think it's due to over-heating, since it happens when the PC should be sitting idle, and it's never happened when i'm actually using the PC. Granted, i don't really do anything that would peg the cpu at 100% for an extended time. But I would expect the cpu to be more heavily used while I'm actually using the PC instead of sitting idle.

I'll try running memtest on it when I'm at lunch or overnight - dont remember off hand how long it takes memtest to run through a few cycles, so not sure if lunch would be long enough for it to stress the memory a bit.

thanks