Plot attached shows TMSX and TMSY damping signals before and after the power outage, and TMSX signals are significantly more noisy after the power outage.
This is a good indication that the noise really did start during the outage, rather than before. In my spectrum post (alog 25062) I mention that I couldn't promise 100% that this noise wasn't there before the outage, since we don't save the data to a high enough rate to look at old spectra.