I restarted the PSL after the power glitch. 

To do this I also had to reset the settings on the KEPCO power supply, and I reset the long range actuator.

When everything locked, the ISS difracted power was around 21%, I tried toggling the noise eater (nothing else on the ODC indicated a problem with the noise eater).  This didn't help, and I ended up adjusting H1:PSL-ISS_REFSIGNAL  to bring the diffracted power down to 9%