[Sheila, Jenne, Kiwamu, Daniel]

It's not totally clear how or when this happened, but at some point today the input pointing PZT driver's power cable came loose.  This box is on the PSL table, in the PSL enclosure.  The failure seems to have happened before anyone went into the enclosure today, but after the fans were turned on (in preparation for going in). 

The big symptom was that we had no light at all on the IMC Refl camera, even though the PMC was locked.  There was no light reaching IOT2L, even at the top of the down-periscope.   We also found that we were unable to move the input beam with the PZT (moving very large steps had no effect on the spot position), and the beam was very low. 

Kiwamu and I confirmed that we were getting signals out of the DAC, so the problem was clearly downstream.

Sheila and Daniel went into the PSL and discovered that the power cable for the PZT driver was loose. The AC adapter for the cable was hanging, with its weight pulling on the power connection on the box.  Jiggling the cable caused the LED on the box to illuminate, and we immediately saw beam on the IMC Refl camera.  Sheila and Daniel moved the power cable, so hopefully this won't happen again.

A bit of alignment later, and the IMC is locked once again.