The other day when verifying rack layout Filiberto felt like something was wrong.  Upon further reflection he came to me this morning thinking he saw the HV shutter drive off.  No readbacks on the lcd screen.  I went out on the floor this morning and sure enough the +-15VDC switch was in the off position.  I turned it on and knocked the IFO out of lock.  At this time I am not sure how long it has been off (will run Dataviewer on a channel.) or why but will investigate.  When we work on this chamber for vacuum reasons we switch off the High Voltage supply so no one should have shut this unit off.   Investigation will continue to see how long we have been running in this state.