Fabio and Suzanne successfully replaced the RF driver of the NI CO2 laser (see Fig 1). To perform the intervention, the 220 V line was completely disabled from the electrical panel in the TCS room and re-enabled once the operation was completed.

The lasers (both CH and DAS) were switched on at 14:31 UTC, and the lost power was recovered (see Fig. 2).

[Nicola took care of re-engaging the Guardian system.]

A thermal image of the rings was acquired for a quick check, and the rings appear to have returned to their pre-blackout conditions (see Fig. 3).

After waiting for the strongest thermal transient to settle, and following a phase tuning performed by Manuel, the CITF locked and the sideband levels returned to values consistent with the pre-blackout conditions (see Fig. 3).

After that, Manuel and Diego started working on the lock acquisition (see entry 68841).