If I'm using battery power, my screen flickers, then goes fuzzy then comes back to normal on a cycle. If I use mains this problem doesn't occur.

When on mains power, if my screen goes into energy saver mode it won't wake up again. If I put my laptop into sleep mode it won't wake up again.

I thought maybe a graphics card issue - NVIDIA GeForce GT 555M, I've got the latest driver installed.

Any thoughts anyone?

Much appreciated.