random laptop power outages with Ubuntu 16.04.1

[Jason Paul Joines]

-------- Original Message --------
Subject: Re: random laptop power outages with Ubuntu 16.04.1
From: Liam Proven <lproven at gmail.com>
To: ubuntu-users at lists.ubuntu.com
Date: 2016.11.30.Wed.13:46:50

> On 30 November 2016 at 19:29, Jason Paul Joines <jason at joines.org> wrote:
>>         When it last crashed I was watching the temperature via
>> xsensors.  Both cores were around 38 °C.  Periodically one would jump up
>> to 56 °C for just a second, but then drop back down.  That seems to be
>> too cool to be an overheating issue.
> 
> You're right, it does.
> 
>>         Although, I left it running Memtest86+ 5.01 last night.  When I
>> came in this morning, the machine was locked up.  It seems like it did
>> not find any errors, but also did not complete a pass:
>>
>> Pass 21%
>> Test 81%
>> Test #7 [BLock_move]
>> Testing:  4096 M - 6144 M    2048 M of 7988 M
>> Pattern:                    | Time: 0:03:34
>> Pass: 0        Errors: 0
> 
> Ouch. That _definitely_ sounds like a hardware issue. I have isolated
> quite a lot of RAM faults with MemTest over the years, and it's so
> tiny that as long as the few hundred kB of RAM that it fits in are OK,
> it runs for days. So either the very beginning of RAM is damaged --
> swapping SIMMs around is worth a try -- or the machine has serious
> issues, probably terminal. :-(
> 
> 


        I re-ran Memtest86+ in FailSafe mode.  It went through one full
pass without locking up or detecting any errors.  Of course, it was only
using one in FailSafe mode.  What is suggested by locking up in SMP
mode, but not detecting any errors in FailSafe mode?  Does that suggest
a CPU issue instead of a RAM issue?


Jason
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