Yesterday, Patrick found HEPI tripped at ETMY. His plots showed the HEPI L4C's rung up. We've been chasing problems there for a while dealing with pier amplification. This morning, I tried bringing HEPI back up and found that the HEPI L4C's would ring after bringing HEPI and the ISI up. My attached plot shows HEPI L4C spectra for the whole chamber isolated  in dashed blue (HEPI on position loops, ISI on level 3 isolated), HEPI postion loops on, ISI damping in green and HEPI off with the ISI isolated in red. Maybe we have a problem with the HEPI loops?