The PRM was pointing totally the wrong way, so there was no light on the oplev PD. I restored the PRM, turned the gains back to (0.15, -0.3) as per Yuta's elog 6952, and it seems just fine to me.
I want to check the data from last night / the weekend to see when the mispointing happened, but dataviewer can't connect to the fb, since Jamie is still working his magic. I'm pretty sure I restored all of the optics after Eric finished playing with MICH Friday night, but it's possible that I forgot one, I suppose. If it wasn't me, then I'm curious when it happened.