The easiest way to find out which diode is faulty is to go into Hardware in GUI and do a Laser calibration at 300mw under Laser. Like this you will find out which Diode is faulty.
pls go to hardware gui/laser gropu/defolt laser factor select/ reset diodes/type 300 or 600 or 900 mw which one i dont know you use and enter the calibrate
you will see on the table colored red if you have defected laser diodes with number