What we need to know, if this happened during normal production, or during an automatic calibration. Normal PMT voltage ( called here Dynode voltage), should be between -630v to -750v. We can see here that the dynode is around -300v. It means that too much light reaching the PMT / PMT’s. Please tell them remove both light shield , disconnect the motor, cover completely the scanner window, to prevent any light to reach the detector, switch off UV lamps, and open the read PMT option (into menu) and read all PMT voltages, turn on the UV lamp (On line command), read PMT again. They can check witch PMT is Faulty.They have to check if there are no scanner window breakage. (This is an UV filter glass).Problem can be with one of the Light shield, too far away from the strip edge, not covering enough the edge.