Recently, my Acer Aspire ZG5 netbook started exhibiting bad behaviour. Within about 10 seconds of turning it on, while it's going through the bootup process, it would just turn off. I researched it on the Internet and came up with all sorts of weird things to try. Like hold this in for 30 seconds, then press this and turn it on, or leave it in the freezer for an hour. Nothing worked.
So yesterday I decided to open it up and look at it. I unscrewed the screws at the front, and couldn't get anything to open. I unscrewed the lid to the memory compartment and looked in there and saw nothing that would allow the case to come off, so I gave up and put the lid back on and screwed the front screws in again.
And it's worked flawlessly since then. And I think I know why. I remember opening the memory compartment just before the problems started. And I don't think the lid fit back on properly. When I removed the lid yesterday, I noticed it wasn't on quite right, and when I put it back, it didn't want to go back on quite right, and I had to juggle it and get it positioned just right and then it clicked into place and I could screw it back on.
I suspect that it's related to that lid. When the lid is on correctly, the netbook works perfectly. When the lid is not on correctly, the netbook turns off after about 10 seconds. I can't see any sensors in that compartment, and maybe it's totally coincidental, but getting that lid on correctly means that the netbook works pefectly again, and I am happy. And it's a more sensible solution than putting the netbook in the freezer for an hour.