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Diagnosing Freezes - Win 7

By Azual · 7 replies
Mar 31, 2010
  1. Hi Techspot,

    My PC is freezing on a frequent basis. I've done what I can to diagnose the problem myself, but I feel I'm reaching the limites of my technical ability. If anyone has time to offer any insight, it would be greatly appreciated.

    I apologise in advance for the wall of text!

    The problem occurs in two ways:

    1 - (90+% of the time) PC freezes instantly, no slowdown, no warning. Usually accompanied by a short, sharp burst of sound or static from the speakers. No bluescreen, no restart, it just stays frozen.

    2 - (less than 10%) PC goes straight to bluescreen and creates a crash dump.

    These could both have seperate causes, I suppose I'm hoping they don't! There doesn't seem to be any regularity to these indicents - frequency varies drastically from every few days to every hour, and there's no pattern in terms of program useage - sometimes I'll be doing something graphic and cpu intensive, sometimes just browsing the internet or occasionally when the PC isn't even doing anything (in fact I just had one while typing this post!).

    The problem became noticeable after a system rebuild during which I replaced my Motherboard and PSU, as well as upgrading to Win 7. However, the system wasn't stable before this (it was worse) so it's possible that the problem existed before.

    What I've done so far:

    - I originally suspected faulty RAM, so I tried running on each stick individually. I experienced crahes with each stick (suggests it's not RAM, unless all 4 have gone or it's a compatibility issue).
    - I ran chkdsk, nothing unusual.
    - Researching the stop errors suggested a software or driver issue, so I ran a clean install, and installed the latest chipset and graphics drivers. Nothing for a couple of days (could point to something I installed after the first couple of days, could be a coincidence - that kind if spacing isn't unusual), but then resumed.
    - I tried swapping the graphics card since I had a spare to hand, no change.
    - Looking through Event Viewer didn't show much that seems suspicious to me. Lots of 41 Kernel-Power (which as I understand it just records that the system shut down unexpectedly) and 6008 EventLog (again, system shutdown unexpectedly). The one thing which may be significant (or may not) are a large number of 11 Disk errors with the description "The driver detected a controller error on \Device\Harddisk1\DR1." - these tie in to some of the crashes but not all. I don't know how significant this is, could the HDD be faulty?

    I guess the evidence points to a hardware fault, however my access to spares is limited and I don't really want to buy anything until I have a better idea what the problem is. I have an old PSU and RAM that I can swap in (I don't have them with me at the moment). I'd be suprised if it was the PSU or Motherboard since both are pretty much brand new, but stranger things have happened. HDD and CPU are both distinct possibilities since these are the oldest components in the system.

    Current system spec:
    Windows 7 64 bit
    Asus P5Q Deluxe mobo (Intel P45)
    Intel Q6600 cpu
    nVidia 8800 GTX
    4x2GB OCZ Gold ram
    Corsair TX 650W psu
    Not sure about the HDD spec

    Error Messages (I've only had 2 that produced crash dumps since the reinstall)


    Problem signature:
    Problem Event Name: BlueScreen
    OS Version: 6.1.7600.
    Locale ID: 2057

    Additional information about the problem:
    BCCode: 1a
    BCP1: 0000000000041287
    BCP2: 0000000000000030
    BCP3: 0000000000000000
    BCP4: 0000000000000000
    OS Version: 6_1_7600
    Service Pack: 0_0
    Product: 768_1

    Files that help describe the problem:


    Problem signature:
    Problem Event Name: BlueScreen
    OS Version: 6.1.7600.
    Locale ID: 2057

    Additional information about the problem:
    BCCode: a
    BCP1: 0000000000000048
    BCP2: 0000000000000002
    BCP3: 0000000000000000
    BCP4: FFFFF80002ACE8A2
    OS Version: 6_1_7600
    Service Pack: 0_0
    Product: 768_1

    Files that help describe the problem:


    See attached for minidumps.

    I have the error messages from before the reinstall, BCCodes were a variety, including d1, 4e, 1000007e, 50, a. Unfortunately I didn't copy the minidumps when I reinstalled, so I don't have those.

    Attached Files:

  2. Route44

    Route44 TechSpot Ambassador Posts: 11,979   +71

    The minidumps did not give a definitive answer to your issues. However with the variety of your error codes there is a strong possibility that your suspicion it is RAM is correct.

    Ox1A and Ox7E are hardware related. Ox50 can be caused by several issues and one of the more common reasons is due to defective memory. 0xD1 are usually caused by faulty drivers but also can be caused by faulty or mismatched memory.

    The single strongest indicator that that there is a high p0robability it is defective memory is the error code 0x0000004E: PFN_LIST_CORRUPT
    This indicates that the memory management Page File Number list is corrupted. Can be caused by corrupt physical RAM, or by drivers passing bad memory descriptor lists.

    So you need to run the completely safe and free memtest on your memory.

    See the link below and follow the instructions. There is a newer version than what is listed but either one should work. If you need to see what the Memtest screen looks like go to reply #21. The third screen is the Memtest screen.

    Let it run for a LONG time. The rule is a minimum of 7 Passes; the more Passes after 7 so much the better. There are 8 individual tests per Pass. Many people will start this test before going to bed and check it the next day.

    If you have errors you have corrupted memory and it needs to be replaced.

    Also, with errors you need to run this test per stick of RAM. Take out one and run the test. Then take that one out and put the other in and run the test. If you start getting errors before 7 Passes you know that stick is corrupted and you don’t need to run the test any further on that stick.

    Link: https://www.techspot.com/vb/topic62524.html

    * Get back to us with the results.
  3. Azual

    Azual TS Rookie Topic Starter

    Thanks for the advice.

    I ran memtest as you suggested, and sure enough it returned errors (quite quickly in fact).

    I just now got hold of some new RAM, and plugged it in. A quick run of memtest (not the full 7 passes, which I'll save to run overnight) gave no errors.

    However, within half an hour of booting up, the PC froze - exactly the same as problem 1 in my original post.

    So, it looks like the RAM was faulty (and probably the cause of the bluescreen crashes) but the freezing, which is by far the more common problem, has a different cause.

    At this point, I'm pretty much stuck. With the exception of the RAM (which I now know is good) and the graphics card (which I've swapped out with no change) it could literally be anything.

    From the symptoms described, is there any piece of hardware that's more likely to be the fault than others? Is there any way I can troubleshoot this short of replacing parts with known good ones until it works?
  4. ryanstrassburg

    ryanstrassburg TS Rookie

    Possibly a bad power supply/inconsistent power issue? You can check power levels in the BIOS so that should be obvious if anything is off or fluxuating heavily.

    I would check disk drives. I had this happen from a loose power cable to on of my HD's, Windwos 7 would just lockup for no apparent reason. In fact I had this happen on XP/Vista also due to a bad power coupler on my old IDE HD. Do you have a Seagate drive? If so is it on the recall list? Just a thought.
  5. Route44

    Route44 TechSpot Ambassador Posts: 11,979   +71

    Also, check the RAM voltage in the BIOS and compare it to the RAM voltage specs as set by the manufacture.
  6. Azual

    Azual TS Rookie Topic Starter

    Power levels seem as I would expect.

    The HDD is a Western Digital, but it could well be the cause. It's one of the few components that's left from my original build.

    It would also tie in with a problem I had prior to this one - my PC would crash and on reboot wouldn't detect the hard drive. At the time I attributed this to the motherboard, which was known to be temperamental and was later replaced which solved this problem, although the current problem began immediately afterwards.

    EDIT: I take it back, not only is it indeed a Seagate (not sure why I thought it was WD) but it's a barracuda 7200.11, which as far as I can tell is the model affected by the recalls you mentioned.

    Not only that, but the problem I just described (HDD not being recognised during boot) seems to be one of the main symptoms of the faulty HDDs that were recalled!
  7. Azual

    Azual TS Rookie Topic Starter

    Just to let you know, the HDD was indeed the problem. Replaced it with a shiny new SSD and the system has been running flawlessly since.

    Thanks for all the help!
  8. Route44

    Route44 TechSpot Ambassador Posts: 11,979   +71

    Thanks for getting back to us. And glasd to see both your issues are resolved.
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