I got a call yesterday from the maintenance man on one of my buildings. They are going to be replacing all of the controls in the building eventually, and he was walking around taking pictures of all the old stuff.
We have Alerton controls running the air handlers. He called to ask why, when he takes flash pictures of the APLC controllers, the air handler for that controller instantly shuts down? He thought it was a coincidence at first, but then repeated it on three other contollers reliably. Reseting the disconnect started the fans back up.
I remember hearing something about old Alerton stuff that could lose all of it's RAM when the chip was removed and exposed to strong light for like 15 minutes, but that is the only guess I have. These controllers are 15 years old.
I told him to stop taking pictures.