Blank screen but brand new PC

[msdontknow]

hey guys, first off my name says it all - i really don't know a lot about pc's.
right here goes - bought a new pc from dinopc and it arrived 2 days ago.
turned it on and it worked fine. installed my game (world of warcraft) and downloaded all the extras, turned it off (properly). following day i played the game with no problems at all and again turned it off properly. however the following day i turned it on and all i got was a blank monitor screen.
everything is exactly the same as the night before and not been touched or fiddled with.
the tower is running and the fan is working but i have no idea what it could be coz its all new. also it cant be the monitor as i tried it on the working one im on now.
any suggestions would be very appreciated.
my specs are -

CPU: AMD Athlon II X4 640 AM3

Operating System: Microsoft® Windows 7 Home Premium 64-bit

Motherboard: Asus M4N68T-M

Memory: 4GB DDR3 1333mhz (2x 2GB)

Hard Drives: 500GB S-ATAII 3.0Gb/s

Optical Drive: 22x DVD±RW DL S-ATA

Graphics card: ATI Radeon HD 5770 1GB

Sound card: Onboard 7.1 Audio

Case: Piano Black ATX

PSU: 500W PSU
thank you very much

 

[CCT]

With a NEW computer and limited computer knowledge it is always best to get it fixed under warranty.

Dinopc -> http://www.dinopc.com/shop/pc/viewContent.asp?idpage=4

 

[treetops]

With a NEW computer and limited computer knowledge it is always best to get it fixed under warranty.

Dinopc -> http://www.dinopc.com/shop/pc/viewContent.asp?idpage=4

I agree however you can try unplugging the power for 10 minutes from the back then holding in the on button to drain out the power for a minute, there may be something up with your set resolution. If this fixes it, make sure you download your windows updates and video card updates before playing wow again. Windows 7 may update your video card for you so I would update that first.

if you happened to bump it and opening the case will not off set the warranty then I would peak inside and see if anything is disconnected

 

[Kaijiru]

I agree that most likely it's a resolution issue. I had the same problem in which I set the resolution too high and my screen was black and impossible to change, so I hooked it up to my t.v which supported the resolution in which case I set it back. If you have some monitors laying around or a proper t.v hookup I would give it a shot