Thanks for posting on the Support Community.
Please could you advise what the projector model is? (Please do not provide the serial number).
Does the image appear to be dull/dim? This could be a sign of an aging lamp, if possible please test another lamp from another projector of the same model and see if the image is the same.
If you are still having issues I would recommend contacting Promethean Technical Support directly and provide your serial number for further advise.
Promethean Technical Support