As part of a renovation, my previous employer equipped all class rooms and conference rooms with InFocus DLP projectors. Some were ceiling mounted, some table mounted, and we had a couple of mobile setups. In all, we had over a dozen.

The DLP modules all failed, with some not even outlasting the projector's first bulb. Things would go perfectly fine, until one day a handful of dark dots would be scattered across the screen. From that point, things usually degenerated quickly until the quantity of dark dots made the output unusable. I don't think any of them lasted beyond 5 years.