"search for signal" permanent since cable fell out!

Dear all

 

I've been using a Dell 2300MP with my new Dell laptop for six week now.  Yesterday, as i moved the laptop, the VGA cable fell out of the projector, I got the blue screen, and since then the projector has been unable to detect a signial from the laptop.  I switched the cable around, tried manual source searching, unplugged and restarted both machines an embarrasing number of times.  Still, all I can get from the projector is the blue screen informing me that its "searchign for signal". 

 

I've tried many different settings on graphics options on the laptop, repeatedly altered the output mode (fn+F8) 

 

All advice would be much appriciated, as im at a loss how to proceed.

 

Many thanks