VAIO goes to sleep by itself

I have a VAIO VPCSB28GA and installed windows 8 and the necessary drivers from sony-asia website. All is working well except that the laptop goes to sleep randomly and this can happen any time, once in an hour or 4-5 times in an hour. It was also the same on windows 7. In control panel also, all options are set never to sleep/hibernate etc. Any help for this?

 

Standby or hibernation? Check the battery, power options, temperatures, etc.

 

I'd also make sure you somehow didn't get Fn locked and are pressing the "suspend" button on the keyboard. Other than that, it'd be useful to check for any overheating symptoms or battery health (I wouldn't know how to do that in Windows so I can't help you there), as suggested above: overheating should cause a shutdown, but if battery has ran its course, it would go into sleep.

On that note, it could also be a faulty power connector that's dropping out so not charging the battery sufficiently well.

Other than that, something messed up in Windows (you can always get Ubuntu on a USB stick and try it for a while to see if it happens there as well).

 

It can randomly go into sleep mode but does not turn off. I had windows 7 and now using windows 8. Same problem on both, so i doubt its a windows issue. Also what I observed, when i hibernate my laptop at night, when turning on in the morning, the battery has drain and I noticed that sometimes the vaio just turns itself on during the night which causes this. It doesnt log in directly in windows, but only shows a grey screen which when a button is pressed takes you into windows. So the point is that it turns on by itself which drains the battery. Any help? Ive seen similar problems elsewhere

 

In the BIOS, if there is a wake on lan option, disable it.

Last resort: go into power management advanced settings and disable all wake timers.