Jeff K. reported a 0.3 Hz comb in the ETMy oplev. Suspecting a bad laser I took a look at the SUM output of the QPD and sure enough, the SUM is oscillating at about a 0.3 Hz rate, 300 counts pk-pk (see attachment). This is usually a first indication of a bad laser (or a laser going bad). I will head out to End Y after lunch to take a closer look and maybe (probably) replace the laser to see if this solves the issue.