P157SM and Multimonitor

I have a p157sm from metabox with a gtx 770m and I'm running windows 8 on it. When I plug in my desktop monitor using a HDMI cable, the laptop recognises the screen but no image displays, only a black screen. Any ideas whats wrong? Haven't used windows 8 before, previously windows 7 only so I don't know if there is anything else aside I need to do aside from plugging it in and changing the settings to extend the screen.

Any help would be greatly appreciated.

EDIT: the Intel Graphics control panel labels my desktop screen as Digital Television IPS235 if that helps

 

Does the cable work for other devices?

 

I am guessing the notebook display is still on. Did you tell the notebook to display output on the external display? Usuallu using the Fn key and another key. I don't have the model, so can't say. Also look for Intel software and see if it lets you set up the external display. And make sure the display resolution is not set to high.

Sometime rebooting with the display attached and on will do the trick.

 

Yes try the hotkey toggle. You should have options for projector only, mirror, and extend; use the function key and Fx key to cycle through the options until you land on the one you want.

 

the Fn + F2? or FN+ F7? I have used this display using the same hdmi cable with a p150hm (my old laptop) and was working fine. I used to run that laptop with windows 7, so I was partly wondering if there was a difference. Windows 8 had recognised that the screen was plugged in and I had changed the setting to extend, however reguardless of setting ( clone or extend), the display was still black. Will try the FN buttons tonight though, thanks for the ideas.

EDIT: No change, tried it with a different HDMI cable as well as the FN hotkeys