Reboots instead of shutting down and unable to sleep?

Hello all.

So my VAIO refuses to sleep - the screen blacks out as expected and the CPU slows down as if it were just about to sleep. However, then the system immediately wakes up again. Even when I choose to shutdown, the computer immediately reboots instead. This is extremely annoying as the only way to ensure it shuts down is by holding the power button. Also not being able to sleep is extremely irritating.

I tried a system restore but the problem persists. It started a few days ago. The only programs I have installed are Skype, Amazon MP3 Downloader and some updates.

I have ran 'sfc/ scannow' from the CMD and ran hardware diagnostics also.

Any help?

 

I don't know about VAIO specifically, but here's what I'd do in general.

Check the BIOS for power related settings. Many boards have a setting that configures action if power is interrupted. If so, pick something that makes sense for you. In may case, I need to RD to my desktop from offsite at random times, so I leave the PC on, and this BIOS setting is to "Restart after power interruption" so it'll restart and be ready for an RD session if/when commercial power fails in the office where I work.

Check your system event log to see what's happening when you try to sleep or restart. There should be a clue there.

Check this KB for power issue diagnosis
About how to troubleshoot power plans in Windows 7

 

What operating system are you using?

Does this help? Windows XP restarts unexpectedly or restarts when you shut down the computer

 

Thanks guys but I took it to a PC repair shop and they couldn't identify the problem, other than it is a hardware fault - apparently would cost £400 to fix (replacing entire mainboard)!!!

Luckily, it's covered on my dad's home insurance and it's being collected for repairs/replacement tomorrow.

I had tried the above solutions and more before taking it there.