Random Restarts

Mr. Analog · January 09, 2011, 03:24:01 PM

Hey all,

I know this is probably the most generic thread subject ever but I gotta go over it again to make sure that I'm not nuts.

So every now and then my Win7 box just restarts, it could be idle, or browsing the web or in the middle of a game *poof* and I'm booting again. Sometimes it just freezes on a screen, like in the browser or in a game, just whatever I was doing frozen in time, sometimes it will do this during a game and it causes terrible sounds to erupt from my speakers (like playing a data CD-ROM in a CD player).

At first I thought the problem was that using an SSD as the boot drive finally caught up to me, but now after having switched to a regular HDD and having had a couple random restarts I'm not so sure.

I'm pretty sure it's not a power issue because all the case lights/fans/mobo light stay on

I'm pretty sure it's not the memory (though I had problems in the past getting Windows 7 to boot with it under the auto-detected timing), I've run MEMTEST and a few other utilities to ensure it works and that there are no borked modules.

So that leaves motherboard, video card, CPU and HDD.

The thing that's bugging me is that when I have hardware logging turned on, nothing is recorded. I'm pretty sure it's not the CPU overheating, it stays at a fairly even temperature even under load, I'm not willing to rule it out but I would expect more consistency if that were failing.

I wouldn't be surprised if it was the motherboard, I haven't exactly been thrilled by the DX48BT2, not disappointed either just not as impressed (but hey, it was free so who am I to complain?).

Personally, I think the primary suspect is the video card, I have a spare one kicking around that I can play with, but I wish there was a better way to consistently test this issue but it's so random.

Anyway, I guess this turned more of a vent session than a cry for help, but if there is something obvious I'm missing let me know.

Lazybones · January 09, 2011, 08:14:48 PM

- did you let memtest complete a full round of tests?
- to be clear, does your system freeze, blue screen or random reboot?
- in my experience a video card will cause a logable or visual error like garbage images or blue screen.

Based on your current report I would try a different PSU, or load a utility that logs power and watch for fluctuation.

Mr. Analog · January 10, 2011, 03:12:22 AM

Thanks, I'll give that a try.

I let memtest run it's full course, yes.

I never get a BSOD it just restarts or hangs

For power testing utilities do you have any recommendations / preferences?

Tom · January 10, 2011, 03:54:18 AM

Quote from: Mr. Analog on January 10, 2011, 03:12:22 AM
Thanks, I'll give that a try.

I let memtest run it's full course, yes.

I never get a BSOD it just restarts or hangs

For power testing utilities do you have any recommendations / preferences?

I use a digital multimeter. Seems to be more reliable than any of the sensors on mobos these days.

Mr. Analog · January 10, 2011, 06:56:49 AM

Quote from: Tom on January 10, 2011, 03:54:18 AM
I use a digital multimeter. Seems to be more reliable than any of the sensors on mobos these days.

I have an analogue multimeter but from what I was reading it's kind of dangerous and I don't have a bench with a ground on it (well, not anything I trust anyway).

I *think* this might be a driver problem actually, I woke up this morning to find my system sitting in that crash diagnostic screen, looking at the output it appears to either be the nVidia drivers or the Intel chipset drivers that I installed yesterday (and previously, on the old build).

Curiously there are no dump files though, like I say, there's no BSOD so I'm guessing that Windows is guessing that it's a driver issue.

I've reverted back to whatever drivers Microsoft installed and we'll see how that goes (should only take one or two days to call it).

I still suspect power though...

Lazybones · January 10, 2011, 07:46:30 AM

FYI I believe the default on vista and win 7 is to reboot instead of bluescreen.
You can change it back to bluescreen however under computer properties.

Melbosa · January 10, 2011, 08:59:47 AM

Yeah was going to suggest that which Lazy says. And for that matter Windows XP is also set to auto-reboot on blue screen.

To change, right-click My Computer, Properties, Advanced system settings (left Nav), (Advanced Tab) Startup and Recovery section Settings button, Uncheck Automatically restart.

Lazybones · January 10, 2011, 09:06:41 AM

Once you have a bluescreen, you will also have an error that you can diagnose... If after that change you still get a reboot instead of a blue screen it is probably the PSU, MB or CPU, since interruptions of power to the CPU are about all that will cause a sudden reboot without a Bluescreen... Nearly all other hardware issues will leave some form of error.

Mr. Analog · January 10, 2011, 11:34:59 AM

I'll enable this and see what there is, thanks!

Mr. Analog · January 13, 2011, 10:48:41 AM

Well, I enabled BSOD and nada, it still just winks off and restarts. I'm thinking this is a power issue now. I'm going to take it into MemEx and get one of their people to give it a looking at where they can test the power on the bench.

Not sure what's up but I'll get this sorted out for good this weekend...

I should also ask them if there is a reason why all four sticks of memory can't run using their native timing settings in the BIOS in Windows 7 but run just fine in Ubuntu/DOS and do not fail MEMTEST. If I have just 4 GBs there's no problem with the timing but if I have all 8 GBs installed Windows won't start (Ubuntu does though...).

Tom · January 13, 2011, 12:29:08 PM

That is somewhat strange. Typically the OS doesn't change memory timings or frequency.. Sure a program later on in startup can tweak some stuff, but it should at least get to the desktop.

Maybe windows is doing some funky stuff with the powerboost stuff? It'll jack up the cpu freq too high and cause a "brown out"?

I've had some really funny things happen on a couple PSUs due to unbalanced voltage rails. Sure the PSU was rated high enough over all, but one rail was overloaded a fair bit, due to too many things sharing the same rail as the CPU and built in PCI-E adapter. It seems my older PSU really did NOT like a Q6600, a 8800GTS, and some other random hardware sharing a rail (I don't blame it). After moving stuff around, things started working.

Mr. Analog · January 13, 2011, 01:26:03 PM

It didn't make sense to me either but the only advise I could find online was to change the timing and underclock the memory, this seems to work.

Why it's only a problem when all 8 gigs are installed and not just 4 is beyond me.

Crazy random thought: maybe the PSU I have is underpowered for the machine I'm running? That would explain a few things. I think it's a 750 Watt PSU. I should look up a power calculator tonight...

Tom · January 13, 2011, 02:23:40 PM

Quote from: Mr. Analog on January 13, 2011, 01:26:03 PM
It didn't make sense to me either but the only advise I could find online was to change the timing and underclock the memory, this seems to work.

Why it's only a problem when all 8 gigs are installed and not just 4 is beyond me.

Crazy random thought: maybe the PSU I have is underpowered for the machine I'm running? That would explain a few things. I think it's a 750 Watt PSU. I should look up a power calculator tonight...

It should have more than enough power. Your issue might be similar to mine. The overloaded rails issue. Many PSUs have several separate voltage rails spread out between the connectors. With one of mine, all of the non modular connectors were on a single rail, which caused that rail to overload if I actually tried to use all of them, so I had to leave the built in PCI-E/GFX connector unconnected, and use a modular PCI-E cable for my 8800GTS instead, that and moving my hard drives around solved the power problems I was having with my desktop. Overloading a single rail can cause a PSU to react the same as if the entire PSU was overloaded (immediate shut off, or a power cycle if it was a short power spike).

As for the memory issue, Many boards will only /fully/ support its rated MAX ram speed with say, half the banks full. Fill it all up, and it wants to either run at a higher latency, or lower freq, or both.

I have found that linux will get further booting with memory errors. Though often (most) programs fail to actually start up on boot, but it actually gets me to a VT, so thats /something/ at least.

Melbosa · January 13, 2011, 03:05:45 PM

Also, 750 Watt PSU doesn't necessarily work at 750 constant or at full efficiency. There is that possibility as well. Over time, I have had PSUs become underpowered, and cause me issues.

Tom · January 14, 2011, 03:45:29 AM

Quote from: Melbosa on January 13, 2011, 03:05:45 PM
Also, 750 Watt PSU doesn't necessarily work at 750 constant or at full efficiency. There is that possibility as well. Over time, I have had PSUs become underpowered, and cause me issues.

Yup, theres that too. Over time they can loose 10-20% or more of their efficiency/capacity. But I think it is /supposed/ to take many years. Guess it depends if the PSU is from the bad caps era, and one or two are about to fail?