Near the end of my shift, H1 lost lock,  with a message about the PMC High Voltage.  I found the Diode Chiller was offit, and the NPRO power clearly shows that it's now off.

The only guardian error message was PMC High Voltage is OFF.

After talking to Jason, I went to the CER and looked at the PSL power supply(s).

• in the C9 rack, there is a power supply that says 374V, 6mA
  • it's sticker says 50mA, but without anything drawing power, the 6mA would make sense
  • Jason confirmed this powers the PMC PZT
  • I mentioned the red light on the front, and Jason believes that means the output is enabled
• in the rack C2, the +-150V PSL power supply is ON
• in another rack, PSL +-18V power supply is on

Power supplies look OK, so it appears that the guardian error message may be a result of losing the chilller.

Attached are pictures of 3 the 3 PSL power supplies.