Mid maintenance, the ETMy ESD tripped off.  I toggled the HV ON/OFF switch on the SUS screen which tunred it on, but in the railed ~-16k state.  I toggled the switch slowly a few times but the railing never cleared.  Richard went to EY and did the old "Power OFF, pull DAQ plug, re-power ON, re-plug in DAQ cable" trick.  It's back now.