FET threshold variations => pedestal shifts, eventually transistors stop switching
FET gain reduction => reduced signal/noise
Pedestals
Note 1: damage varies across hybrid according to height of readout channel above the beam axis, but the decoupling circuits cause only the differences to be seen relative to the average shift and therefore both extremes are offset
Note 2: electronics polarity of ZA, ZB reversed with respect to Phi
Note 3: damage would have been signicantly worse if the electronics had been switched on during this period