sanyo projector fault

[dextermain]

just started having a problem with my sanyo pro-x svga projector possibly plc-xu56 or 51 or su 51. when starting up light is purple as usual, when connecting computer the light goes to green, have made sure blackboard icon is unchecked, also have reset to factory settings, still no joy, if any body may have some clues would appreciate the advice. cheers