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  1. Conundrum1885

    Add your tech anomaly here

    Hi all,

    Finally found out why my laptop was randomly crashing/misbehaving/etc, turns out that (a) webcam had an apparent intermittent fault causing BSODs on recovering from Sleep, and (b) the 4GB 2*2GB DDR3-1066 was damaged and apparently overheating causing (c) the BIOS to switch from AHCI to IDE mode resulting in OS corruption.

    Removed webcam and a lot of the problems went away, changed RAM and this fixed the rest.

    Now Itunes runs stably without crashing, Firefox also doesn't crash any more with lots of windows open.

    The really strange thing is I just had the exact same fail on my 5230, webcam causing BSOD on recover from Sleep yet it works fine when removed.

    Is it possible that my proximity is breaking the machines somehow because this can't just be coincidence.

    Both cameras made by Chicony if this helps and contained similar 512Mbit memory 8 pin SSOP.

    A similar problem ie AHCI to IDE switch also occurred on a desktop near where I work and this machine also uses DDR3 yet it has been working perfectly until then.

    CMOS battery checked out fine, no-one seems to have been fiddling with it.

    I also had an HP spectrum analyzer break at 'Uni once, displayed all the symptoms of a failed main IC which at the time would have been an expensive (£300+) repair requiring days of downtime.

    Upon going off for my lunch it upon reboot recovered just fine and never did it again (!)

    Reading up about the "Pauli Effect" makes me wonder about a possible paranormal connection, but surely there has to be a rational explanation right?

    -Andre

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  2. Conundrum1885

    Update 29/03/15

    I'm not discounting the possibility that it might be some sort of EMI because there are a lot (as in 3-4 a day) of 3G dropouts here.

    Tested microwave for leakage and it came back as normal but did notice one of the lights very close to the flat was splashing the area with wideband RF interference.

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  3. Conundrum1885

    Update 25/08/15

    Might have found at least one cause, defective RAM.

    Not just any defective RAM, poltergeist defective RAM that passed extended memtest86+ BUT showed glitches in the graphics so the fail is likely to be in the first chip on the 2GB stick.

    Possibly temperature/speed related as when testing while "hot" it showed clear signs of damage on one machine and not another.

    I suspect that it might have been damaged by a close lightning strike earlier that year, it was severe enough to murder the network card and router (also overheating) but as the laptop was just sitting on a glass table near the main PC thought nothing of it.

    Its also worth noting that this machine also has the same model of webcam, so it might be worth if you are also experiencing intermittent faults like this to remove the part from affected laptops (Acer, Samsung, HP) and see if the BSOD's go away.

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  4. Anonymous Coward
    Anonymous Coward

    That was no lightning strike. That was the signal from mars for the buried Martians to awake and start attacking. The first line of attack is to cause random BSOD to cripple the Indian telephony network and send computer literate people insane.

    The Pauli effect exists for anyone who is always looking for it.

    1 0 Reply
    1. jake Silver badge
      Reply Icon

      @AC "1 day" (whatever that means, ElReg)

      "The first line of attack is to cause random BSOD to cripple the Indian telephony network and send computer literate people insane."

      Did you missplel "illiterate"? I have never, in my entire life, seen a computer literate person see a BSOD on their own personal system, including personal systems at work. Development systems, yes. But a personal "my desktop" box? Really?

      1 1 Reply

      1. This post has been deleted by its author

  5. jake Silver badge

    "Define computer literate."

    Someone who actually knows how ones & zeros tell the hardware what to do.

    EOF

    0 4 Reply
    1. Anonymous Coward
      Reply Icon
      Anonymous Coward

      Re: "Define computer literate."

      This from the guy who thinks moving components from kernel space to userspace introduces massive security holes...

      0 0 Reply
      1. jake Silver badge
        Reply Icon

        @AC "17 hrs", whatever that means ElReg (was: Re: "Define computer literate.")

        So, Mr. Coward, can you tell me exactly why you think that allowing userspace to directly access hardware is NOT a security risk?

        ::crickets::

        That's what I thought.

        0 3 Reply
        1. Anonymous Coward
          Reply Icon
          Anonymous Coward

          Re: @AC "17 hrs", whatever that means ElReg (was: "Define computer literate.")

          Can you explain why punching bloody great holes through ring 0 isn't? In userspace, a driver can only access the hardware to which it is granted permission. It can't easily escalate privs, it can't meddle with kernel memory and if it's badly written it will only crash itself, and theoretically can be restarted without the entire system going to shit. In the ideal state (which I grant doesn't exist in the real world) it can't do anything except what it's allowed to do.

          In kernel space it can do all those things and a great deal more. Windows NT 4.0 and over were severely compromised in both terms of security and stability when the graphics stack was moved into kernel space from user space in an attempt to improve graphical responsiveness. Many of the biggest flaws in NT from then until NT 6.0 have been related to exploits of the graphics subsystem, nearly all of the stability problems encountered in win2k and XP were related to graphics drivers knocking down the entire system. Since 6.0 those issues have been largely mitigated by pulling the majority of the graphics subsystem back out into userspace.

          In the security trade-off between "has direct access to a single piece of hardware" vs "has direct access to EVERYTHING", the former wins every time.

          0 1 Reply
  6. Anonymous Coward
    Anonymous Coward

    Random

    Maybe why if you unplug an active device like an SDR, USB DVD drive, etc it BSODs one time in n where n is a large number.

    0 0 Reply
  7. Anonymous Coward
    Anonymous Coward

    Also relevant

    This machine is literally well beyond "normal" EOL and as running W7 is already obsolete.

    I once (!) tried installing 10 on it back when the drive got swapped after failure, no hope. Installed uo to 94% then rebooted and Adios Muchachos. Black screen, no drive lights, nothing apart from a tiny white cursor on the top left of the screen.

    0 0 Reply
  8. Conundrum1885

    Update

    Got it to work, the combination of latest W10 x64 and turning off a specific BIOS feature called "DEP" did it.

    Turns out that on Samsung laptops of this era, DEP includes other things that aren't listed.

    Turning it off will also get Ubuntu >13 x64 installing as well.

    Runs fine now.

    0 0 Reply

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