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Re: Laptop randomly reboots

On 09/05/2017 06:25 AM, rhkramer@gmail.com wrote:
On Tuesday, September 05, 2017 12:46:58 AM Sam Smith wrote:
Well I guess I really spoke too soon.... Just got a random reboot a
minute ago... Pretty much at a loss now. The only thing that hasn't been
replaced now is the CPU, battery, and power adapter. I do have a spare
battery and power adapter. Guess I'll try running with those for a month
or so and see what happens. Though not really sure how either one of
those would make the computer reboot randomly once a month. Laptop is
mounted in a docking station. At least for the last 6 months, every
reboot was while it was docked. But I do remember times last year
sitting at the kitchen table undocked and getting a reboot so I don't
think the docking station is the issue.. But have no idea now :/

I haven't paid much attention to this before today, but, if I had a problem
with unexplained reboots, the first area I'd look at is the power supply
"chain"--that is, the battery, the connections between the battery and the
laptop, power "glitches" to the house,etc.

I run a laptop with a known bad battery--if I disconnect the power supply it
crashes in seconds.  OTOH, if your battery is good, it serves as a (long
lived) UPS--you should be able to ride out hours long power glitches.

If I had a known good battery, I might try examining the contacts between the
battery and the laptop--are they clean / shiny, is the "springy side" still
"springy", does the battery fit snugly in the case or is there enough clearance
for it to possibly move and break contact with the laptop?  I might even try
picking up the laptop and reasonably gently shaking it (while running) to see
if it reboots.  (You don't want to shake it so hard that you damage something

If you have a known bad battery, I'd look at the chain from the power outlet
through the various cords and contacts on both sides of the power adapter.
Try shaking the power adapter.

Is the power to your house reliable--is there any chance you've had brief
power outages overnight?  (In the US, most electric utilities have automatic
reclosers on the power line circuit breakers--if they detect a fault they
open, then try closing again after a few seconds (in hopes that either the
fault has cleared (maybe a shorting tree branch has either blown or burned),
away, open again if there is still a fault, again try to reclose, after a few
seconds.  In most cases, they try this something like 3 times, with a somewhat
longer delay before the last retry.

Oh wait, you have (presumably known good) spare battery and power adapter--try

The power "chain" imo seems good. Never heard of a power adapter going bad.. but I do have a spare. The battery I normally use is a smaller 6 cell I bought off of ebay, it is pretty wore out. It reports 50% capacity loss but runs for about 2 hours. I only bought it because the stock battery is a bigger 9 cell that is bulky and heavy so around the house I just leave the smaller one in. I'll use my spares for now. As for household power, it is normally plugged into my UPS (apc smartups, not the cheap consumer version).

CPUs seem pretty cheap on ebay, so I could try that. But it seems that CPU issues would cause more problems than a random reboot once a month.

One other thing, I do run the 'thinkfan' fan control program. You can set fan levels by temp. It was made for thinkpads made probably 10 years ago, but still seems to work on the newer models. But I do know the embedded controller on the T520 series is different than prior models. So perhaps taking control of the fan causes the EC to detect this as a fault. And maybe, just maybe, after so many "faults" it will kill power to the machine. A wild idea but who knows. I've also since disabled the thinkfan service.

Other than these, not sure what else. Kinda strange, but definitely annoying.


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