(Sheila, Chris) Recently the input alignment to the IMC was disturbed slightly by a test of the PZT on the PSL periscope. After the test, the PZT was returned to its original state (unplugged), but it did not come back exactly to its original position. This misalignment was interfering with our efforts to lock and align the mode cleaner, so Sheila consulted with Rick and Michael, and we got permission to enter the PSL enclosure and reconnect the PZT. We did exactly that, and then went to IOT2L to search for the MC reflected beam. However, the beam seems to be missing the table altogether, so we were not able to recover the alignment as easily as we hoped. We gave up for tonight, left the PZT plugged in and closed the PSL shutter. Tomorrow we'll have to start by recovering the alignment coarsely (e.g. by using a viewport reflected spot as a reference).
For future reference: You can scan the PZTs.
Set PIT frequency to something (e.g. 1Hz), YAW frequency to something different and not an easy integer multiple so that (P,Y) comes back to the original position after somewhat long period of time (e.g. YAW freq = 3.31 Hz), wait for a while, make a trend of WFS DC, IMC REFL DC, PIT and YAW offset. If the alignment is within PZT's range you will find the beam.