Hi,

I have a problem with an All-In-One desktop computer (PCG-11211M) which I had for quite a while.
Recently screen has started to play up.

When I turn it on it's just black. Nothing comes up, not even the VAIO logo.

Now the funny thing is that if I press display On/Off button which is located on the top left corner of the computer screen flickers.

It turns on for about a second then goes blank again.
Then I have to turn the screen on again and once I press the button to turn it off it clickers again doing exactly the same thing.

No artifacts on the screen itself, everything is crystal clear it's just the fact that it doesn't come up.

Could you please advise on what could be the problem or what kind of test could I run?

Please note that I already reset BIOS settings (had to constantly turn the screen on and off to see what I have to press) but this didn't help.

This is not driver problem as BIOS doesn't load drivers.
I doubt that this is the video card itself as when it does flicker the image is crystal clear and if video chips itself would be faulty then there would be some artifacts on the screen or it wouldn't turn on at all.

Please recommend what other tests I could run.
Don't be afraid to suggest advanced tests. I am an IT technician and can easily run any test you suggest.

Hope to hear from you soon.