Power off after exactly 30 seconds (solved!)

So we had a problem today on a friend's Aspire One that I'd like to pass on in case anyone else encounters it. I found at least two other instances of it described on the net. Maybe this is even a common problem, but I haven't seen the solution yet.

The behavior is that the machine powers off exactly 30 seconds after the first BIOS boot information shows up on the screen after powering on. It happens if you let it start to boot into windows, or even just enter the BIOS setup and leave it.

Having had one of ours power off suddenly when running a game and with the air vents blocked, my guess was that it's a problem with the temperature sensor. I believe that the BIOS enables a hardware temperature failsafe that will cause the power to be yanked if a "high temperature" condition exists for more than 30 seconds. Further, I believe the temperature sensor, whatever technology it uses, does not always fully reset when the temperature returns to normal.

So a system which has experienced a high temperature may get the sensor "stuck" at which point you'll see the 30 second shutdowns.

Based on this wild-guess at the problem, I put the laptop into a 1 gallon zip-lock style bag and stuck it in the freezer for ten minutes.

That seems to have solved the problem completely.

G.

 

My AAOne started doing that today. (I haven't time the exactly 30 seconds part, but it's close.) I'll try that and report back.

Thanks!
-TNFalcon

 

BINGO! I did that and it's fixed now. Thanks for the tip.

-TNF

 

My 8.9" netbook was also shutting down after 2 to 30 seconds of rebooting. Tried the freezer bag trick and it works. This is a great idea!!!!
Sri.

 

I'm experiencing the same issue. However, the ziplock in the freezer trick seems to only extend the time to about 1-5 minutes before resuming the 20-30sec shutdowns. what should I do at this point?

 

If it were me, I'd probably try a longer time in the freezer. There might be hazards though and offhand I don't know what the lowest allowed storage temperature is. If it's fully sealed up in a waterproof bag then it probably would be fine, but if you get it very cold then like any electronic device you should let it warm back up to room temperature for a few hours in case there's condensation inside as it warms up. I would remove the battery before cooling it too.

No warranty expressed or implied, your mileage may vary

In the end though your problem might not be curable through this technique.

G.

 

Your fan most likely is not working

 

Left the computer in the freezer for a few hours. still had the same issue. Is the temperature switch were trying to reset able to be disabled? Also, how to repair a non-working fan?

 

Temperature switch - replace the motherboard

Non working fan - replace with a working fan.

 

Wheres the temperature sensor mounted? in the CPU die, or?

 

This is a really interesting question to which I don't know the answer. My guess is it's not using the CPU's on-die temp (if any) since I would expect that to be a lot more reliable than is suggested by the number of people having this problem. So my guess is it's something on the motherboard. If anyone knows I'd sure like to know, since I'm curious what technology it uses that even has the potential to fail the way these seem to be.

G.

 

It is part of the CPU, see page 5
ZG5 Computer schematic
http://vassyl.net/work/acerone/aspire0nemb.pdf (Thanks Mali)

 

how do I contact ACER for repairs of my ONE? or should I just buy the new mobo and install it myself?

 

If it is under warranty then for sure call Acer.

If it is not under warranty, I believe Acer would charge you more for the motherboard then a new computer could be bought for. In this case install another motherboard yourself.

 

But if you look at that, there's this guy:

http://www.gmt.com.tw/product/datasheet/EDS-780.pdf

which has its own embedded temperature sensor in addition to being able to monitor another source such as the CPU's thermal sensor.

G.

 

Someone who can read and understand the motherboard schematics might be able to determine a hack.

The hack could be something like adding a resister between point A and point B, which tricks the computer into see only one temperature. Or even adding an external thermal diode that would function the same as the internal diode.

 

I had the same problem and it continued after a few days, so I reformatted my HD and it solved the problem.