Roberrt

depends on how dusty the filters are. if theyre very dusty, it can overheat the projector and shortens the life of the bulb. we have 18 of the orange sanyo promethean projectors in our school and some went very dark with blue and pink on the whiteboard. we replaced the lamps, no joy and our rep told us we needed new projectors. They just needed a deep clean and they turned out as good as new. only found this out after buying 3 new projectors. The company we sourced called in to the school and did them on site for us.