BSODs - dead Mobo?

billee

billee

billee

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Joined
1 Sep 2009
Posts
5
Hi,

I could do with some help validating my thinking around some BSODs I've been receiving on my Vista 64 machine (from OCUK, <2 yrs old). The history is as follows:

  • Regular BSODs were occurring - 90% of these were "IRQL not less or equal"
  • The screen would flicker and then it'd BSOD
  • The PC could restart normally and in safe mode but would BSOD during use (sometimes soon after the restart, other times after hours had passed)
  • No new software had been added, no drivers updated for weeks
  • Temperature was fine
  • Chkdisk /r found nothing wrong
  • Memory checks found nothing wrong
  • Device manager said there were some issues with the CD/DVD drivers but it worked ok and Windows was stating it had the latest drivers
  • Things got worse - now it won't boot at all - "21a session manager failed to create protected prefixes system terminated unexpectedly with a status of 0xc000003a" - this always occurs
  • Attempting to boot from a Vista recovery CD throws an unexpected I/O error. The CD checks out ok on other machines and I've tried using an external, USB DVD drive too but with the same result.
  • All combinations of memory tried - one stick, two sticks, different slots etc
  • All peripherals unplugged
  • Disconnected HDD and tried to boot from CD - still get the I/O error
  • Disconnected DVD - still get the 21a error


I haven't tried booting from a recovery USB key but I'm not expecting anything to change. I was thinking this was a bad HDD but the fact that I unplugged it and there was still the issue makes me think it's more likely the mobo. Does that sound likely to folk or are there more likely alternatives? The fact that I can't get into Windows at all now means I'm very limited in my diagnostic options so I'm seeking others opinions before I stump up for new components.
 
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Tonester007 said:
The 21 error suggests your HDD is failing. Do you have an option in the BIOS to turn on "SMART" monitoring for your hard disk?
Click to expand...

Yes - now enabled but nothing appears to have changed - if there's any warnings, I can't see them.

Just running SeaTools now (bootable version so now know dvd is solid). Quick test suggested no issues whatsoever with the HDD. Now running the longer test.
 
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IRQL_NOT_LESS_THAN_EQUAL is normally related to memory problems.

You've already checked your memory with Memtest86+ band various configurations.. but try the single sticks in different slots and so on.

If one stick of memory fails in all slots, then its almost certainly a RAM problem. If the working RAM stick works in one slot but not another, then this is certainly going to be a memory controller problem .

Check that the memory is set correctly i.e. Frequency, VDIMM and latency timings. Check the manufacturers website for details.

If your memory looks ok, then you may need to check your PSU:

http://www.huddysworld.co.uk/index.p...ware&Itemid=72

If you can boot into your system via safe mode, then take a good look at the system dump and Event Manager for clues. Event manager is often overlooked and under estimated.
 
I've tried the memory individually but it made no difference.

I can't get into Windows at all now - that 21a error always occurs - so can't look at the event manager etc. I did check before it got this bad and there was nothing in any of the logs.

I'll look at the PSU now.
 
PSU seems fine.

I'm leaning away from this being hardware now - I think I've effectively proven each major component now (feel free to correct me though).

I feel it's actually a Vista issue but my recovery disk can't get past that I/O error. I've burnt another copy and that gives the same result. But bootable tools such as Memtest and SeaTools all work fine.

Any ideas?

I'm going to try to run SysClone and Ultimate Boot CD to see if either of those highlight anything.
 
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