Hardware/OS CPU: Intel i5 4670K Motherboard: Gigabyte GA-Z87M-D3H RAM: 2 x 4GB Corsair Vengeance 1600MHz 1.5V 11-11-11-30 (CML8GX3M2B1600C11) GPU: HIS HD 7850 IceQ 2GB PSU: XFX Pro Black Edition 750W SSD/HDD: Samsung 840 EVO 250GB (OS) / Seagate Barracuda 1TB (data) OS: 7 Pro x64 SP1 Problem Description Just before Christmas I helped my girlfriend build a new PC. It was with me in Derby for a few weeks over the holidays then went with her to London, where she's studying for a degree. While the PC was here it was stress tested with Prime95 and Furmark, as well as being used to play games she'd had for Christmas, and it ran perfectly, with good temps. Since it's been in London however the PC has started freezing randomly. When it freezes it's completely unresponsive and has to be restarted with the power button. If there's any audio output at the time it too freezes but continues to be output (a constant noise) until the system is restarted or shut down. The fault is irregular and unpredictable, the longest period without a freeze (since they started) was about a week or so and the most to have occurred within 24 hours is three. On average they are now occurring about 3 or 4 times a week. The freezes have occurred both shortly after startup and when the computer has been on for several hours, but she tends to have it on 24/7 so it's predominantly the latter. They have occurred when the system is under load and when it's idle. There are no crash dumps following the freezes, nor are there any events preceding them. The only obviously associated events are afterwards regarding the restarts that follow (because it did not shut down properly). Nothing came loose in transit, everything is seated correctly internally. Kaspersky Internet Security is installed, as is MBAM. Scans have been run with both and there is no sign of malware or viruses on the system. So far she has not run memtest, although I've told her to just to rule that out. The memory timings in the BIOS are correct, as is the voltage. The BIOS version is F8. F9 was recently released, but as yet she has not updated to that. Since the problems began she has checked temps and stress tested the machine again; temps are still all good. The system is fast, responsive and stable when it's working. Both the CPU and GPU are at stock for the time being. I'm really not sure what's causing this behaviour, and I can't just take a look because of the distance. The PC is needed for university work, not just entertainment, so I really want to get this sorted for her. The intermittent fault means she can't trust the PC, she never knows when it's going to fail on her, and she could easily lose unsaved work as a result. If anyone has any ideas as to what could be causing this I'd really appreciate your help. I've suggested she tests the memory, and that she tries a selective startup. I thought she might also try running linux from a CD/DVD to see if it still freezes outside of Windows. The unpredictable and infrequent nature of the fault obviously makes troubleshooting difficult because it isn't immediately obvious whether or not the problem's still there. I wondered if the GPU could perhaps be to blame, but honestly I'm just clutching at straws and trying to rule things out. She could remove it and run with integrated graphics to see if the problem persists. I know this a long rambling post, so thanks for reading it I've tried to mention everything I think's relevant but if you think I've missed something or you need more info let me know.
If testing the RAM doesn't bring up a problem then ruling out software issues is a good idea, but that's next to impossible while still maintaining normal use of the machine. Next step is to try and swap out every component bit by bit. Run off a HDD not the SSD. Swap SATA ports. Remove half the ram (then the other half). Use a different GPU, a different PSU. A different CPU if you can. But first... If it was me I'd try a clean install. Yes I know you've already got a clean install but many a clean install are not really that clean as the first thing people do is install a bucket load of additions. What software is installed? What services are running at startup? How stripped back can you make it and still allow the machine to be used.
Thanks Guinevere Yeah maintaining normal use is the problem because apart from uni work it's also her main source of entertainment, I was hoping advice here may minimise the amount of trial and error required to isolate the fault. I have a spare SSD I can send her to put a clean installation on, and she can take the GPU out and still use the PC for work, but swapping out other components would be difficult as we don't have spares. The current installation has things like the AV software I mentioned, Firefox, Thunderbird, Open Office, Skype etc., plus a few bits she needs for uni like Visual Studio. I'll post back when I have more info from her.
I had a very similar problem recently: http://forums.bit-tech.net/showthread.php?t=266734 It turned out to be a failing PSU... so that would be my guess.
Multiple passes with memtest show no errors so I think it's safe to say the memory's not the problem. We're going to try to rule out the SSD next, although I guess that's going to take some time. I'll post back as soon as there's an update. Thanks for all your help
Check your event manager for an IASTOR ERROR. Had the exact same problem with my SSD when it was first installed years ago, solution here... http://forum.crucial.com/t5/Solid-S...eze-ups-in-Windows-7-solved-for-me/td-p/38766
Thanks Gary, it looks like if we rule the SSD out I'm going to have to swap my PSU with hers to see if that's the issue. It went a little over a week again without freezing then did it three or four times within a couple of days. I hate intermittent faults.
So, it's been a while and the problem's still there. Neither the SSD or PSU have been ruled out yet because she's more interested in playing The Sims than troubleshooting the problem Anyway, I did get her to try running with integrated graphics to rule out the GPU, and that's resulted in slightly different behaviour. The PC froze again with the GPU removed, but this time the display was messed up and flickering, as below: Previously when the PC froze the display would be static, without any artefacts. It's safe to say the GPU's not to blame since the fault persisted without it. The plan is for her to bring the PC back to Derby in a couple of weeks (Easter holiday) so I can look at it for her, in the meantime does the new information give anyone any ideas?
Well it's been ages since I last posted an update on this but it's been a very slow process trying to isolate the fault due the PC being about three hours away most of the time. It's been back here briefly a couple of times and I've had to fit in as much testing as possible while I've had it. I was able to swap everything out and test with a different PSU, a new SSD with clean install etc. and the fault persisted every time. After ruling everything else out I went back to what I suspected originally: the RAM. Although it had passed Memtest and Prime95 without issue previously it hadn't been swapped out or the DIMMs tested individually. Anyway, long story short.... .... I was wrong With my memory installed the PC worked fine, it was left on 24/7 for about a month to be sure that all was well. Satisfied that the fault wasn't present with my RAM we then tested her two DIMMs individually and found that one of them causes the system to freeze when it's installed (the other one works without issue). I can't believe how long it's taken to get to the bottom of this, but it does appear finally to be sorted The next step will be to sort out a replacement from Scan, and then she can go back to wasting a perfectly good PC on The Sims.
