Share 'Weird projector issue--anyone have this?'

I'm hoping someone can help me.  We have a SMART Board with a Unifi 55 projector.  In the spring it started doing this weird flashing, where for a split second the colors would invert like a negative and then return to normal.  At first it was only occasional.  Then it started doing it more often, until it was almost constant, and then the projector would only run a few seconds more before shutti…