Sanyo PLC-XU70 projectors going faint

[Zourous]

I've had a couple of these in the last few days reported. In one of them I've installed a new bulb (despite only 500 hours clocked up on the old one) and it doesn't seem that much brighter. The other one the teachers seem to think it's got fainter overnight. I've checked eco settings and other relevant bits on the menu but I can't pin point anything. Do projectors also go fainter with age, despite bulb changes?