This weekend while I was on Guatemala just a few hours before to give a talk, my acer one decided to suddenly shut down, I tried to started again, remove the battery, plug the charger, etc, I actually even tried to boot it with some liv-usb distro, but the netbook keep shutting down a few seconds after boot 
I’m still not sure what happend to the computer, it could be the motherboard or the HDD, I still have to check if it can be fixed…
Sadly, this was my «main» computer, I always used for almost everything, even for task when building a package tooked 50 minutes :p, but I’m lucky since I did not loose any senssitive data (in case the problem is the HDD), and I still have other computers where I can work, but I still need to get used to a bigger screen/keyboard.
What’s the temperature like there? I had a problem like that with a Thinkpad once, the CPU fan broke and it just shut down due to overheating every time it started – but the system was usable in cold weather even before I had it serviced.
Also theoretically you could get the same result from damage to the thermometer.
Hi,
had the same problem, turned out that after a little hit, the fan was stuck, so instead of melting down it just power off after few seconds. I just needed to open it (thousands of screws) gently touch the fan with a screwdriver and it was back to life.
Hope it helps.
I had a similar problem with my Acer Aspire One. I noticed that previously, the fan had always started up by default, until software control shut it down as until it became warm enough to need it. When I hit this problem the fan never started up. I theorised that the fan had become stuck and as a result was pulling too much current, causing thermal shutdown of the power supply. I disassembled it, cleaned the fan and re-seated most of the connectors. I don’t know whether my theory was correct, but it has not gone wrong again since. Worth a try.
Mine died two weeks ago and like you I have been using the Aspire One as my main machine. I replaced it with an Acer 1810TZ and haven’t looked back. Its a fantastic machine, still light-weight (1,4kg), more than six hours battery life and a dual core inside which is much faster than the Atom. Plus the LCD is 1366×768.
In case you come to the grub but not further (say loading the linux image) this might be the ram it sounds broken
Make a memtest with it.