[mythtv-users] HELP! 64bit Mythbuntu spontaneously reboots (32bit didn't)

[Bert Haskins]

On 08/08/2012 02:44 PM, Patrick Ouellette wrote:
> On Sun, Aug 05, 2012 at 04:44:54PM +1000, Kingsley Turner wrote:
>> Hello again,
>>
>> I think I've determined the culprit - sort of.
>>
>> It wasn't the power supply...  $200 wasted.
>>
>> I used to run xscreensaver with the opengl photo-panning applette.
>> I was sitting around cogitating, watching the screensaver pan over a
>> photo, and the box rebooted.
>> I checked the schedule - it wasn't recording at the time.
>>
>> So I disabled xscreensaver - and thereby "fixed" the reboots.
>>
>> It's now been up for nearly 48 hours, which hasn't happened for
>> weeks - it got to the stage where it would last 2-3 hours at most.
>>
>> So of xscreensaver is causing the box to reboot (As JWZ says, there
>> is nothing in xscreensaver that should cause a problem with X, (let
>> alone a reboot)) - this means it's probably the nVidia blob right?
>>
>> I'm using a motherboard with an on-board nvidia 9400 GPU.  The
>> drivers are the Ubuntu module shipped ones "+updates".
>>
>> Maybe I should change to the latest manual nVidia drivers ?
>>
>> What do you think ?
> I doubt the nVidia blob is the issue (might be, check the nVidia forums
> for the issue), unless you just updated it and then the problem started.
>
> CLEAN YOUR CPU HEATSINK -  Make sure CPU fan(s)/airflow are good.
>
> I had a box doing something similar.  I replaced the power supply, and was
> pulling my hair out trying to figure out why it was randomly rebooting.
> I installed the sensors package to monitor CPU temps and found it was
> overheating (getting to the ACPI BIOS critical temp).
>
> My symptoms: seemingly random shutdowns/reboots with a decreasing time
> between them.
I have seen this several times and the problem was that the small
capacitors surrounding the CPU were dying.

If the tops of the aluminum cans are even starting to pop up
( they should be slightly depressed ) or if there is any sign of
leakage they are on their way out.

If you have a choice, such as when buying a new motherboard,
always go for the solid caps.
>    Didn't seem to matter if I was watching a show or the
> backend was idle.  I later found it would reboot during a CPU intensive
> application (transcoding for instance) every time.
>
> I also noticed the "upgrade" from Ubuntu 11 to 12 revived my automatic
> shutdown command for myth backend so the backend would shutdown after
> the timeout - I had disabled that (at least I thought I had) before the
> upgrade.  After cleaning the CPU heatsink and  disabling the auto backend
> idle shutdown the box has been rock solid.
>
>