J. Kissel, T. Sadecki Yesterday, while reinstalling and aligning the H2 SUS ITMY M0 and R0 BOSEMs, we discovered that the M0 Right OSEM sensor is railing. Here're the facts: - This is BOSEM S/N 499, according to LHO aLOG 972. - The signal coming into the ADC is railed, at *exactly* 2^16 (as opposed to if the OSEM were just reading its open light current). - The previously measured open light current for this OSEM is 26205.8 cts, or 66 uA. - Disconnecting the cable from the BOSEM at the micro-D, in vacuum connection does not effect the signal, i.e. railing regardless of OSEM or no OSEM. - There are no fault lights present on the satellite amplifier boxes. - The satellite amplifier has been modified, as per G1100856 - Driving in vertical shows that the actuator side of the OSEM is still functional. - The last time we've looked at signals from this OSEM was just before the fiber break, in mid October. This should be fixed ASAP.