Sorry to hear about that. There is an light sensor on top of the gantry that sends light out on one fiber optic cable, shoots across the beam path, then the reflected light is picked up by another fiber optic cable then sent back. The light level has to be in a certain range or the lens burn out alarm is generated.
It's possible the end of the cable got some lens dust on it, or got burned a little. That's why the alarm isn't going away.
There is a procedure for cheching and adjusting the light meter. I will email it.