After about an hour of it being on it just turns off I can't turn it back on with the power button the only way I get it back on is unplug it and plugging it back in and then it shuts down is about 40 min (repeat what I did) eventually it will just not be able to turn on and I have only had it for about 3 months so its not old at all.

So I was just wondering if any of you know if there is something I can do about it thanks

p.s. I have put another monitor on my computer and it works fine so I am sure it's the other monitor that's the problem just wondering if there is anything I can do about it

It seems you've already solved the problem by determining it's a monitor issue. To make absolutely sure its NOT the PC or video card, try the problem monitor on another computer.