Interactive WhiteboardsBlank screen on whiteboard

Hi Nicola, 

If you are getting an image, even if it’s dim and out of focus, then at least the projector is working. 
The next step would be to test the projector with another lamp from a projector of the same type if you have one handy. 
This will rule out the lamp needs replacing. 
Also check the vents and filters to make sure they are clean and when the projector is turned off and cooled down, also check if the lens is clean. 

The best thing to do would be to get the projector serial number and call in to our Technical Support with the reference I provided above. 
They will be able to check the warranty and advise the next steps once you have tested it with another lamp.