I had to go home in the afternoon, so we couldn't do any alignment work, which should be done on Monday. EY is in laser hazard.

We did check the beam diverter. (This one should be replaced anyway, but not before moving the entire EY to H1 position. https://services.ligo-wa.caltech.edu/integrationissues/show_bug.cgi?id=83)

Beam diverter is connected to F2-2C2 feedthrough on BSC6. From outside, pin1-14 is the coil, pin2-15 is one of the reed switches (SW1), and pin3-16 is the other (SW2).

When pin1 is positive and pin14 negative, the beam diverter moves from "open" position where the mirror is tipped toward EY to "closed" position where it is tipped away from EY.

However, we've found that pin1 is short-circuited to the chamber and the building ground. This means that you need a floating supply to drive it (which is not a problem for a proper driver but is a problem when you're using a power supply with one of the pins grounded). If for example the negative is grounded and if you try to "close" it by supplying positive to pin 1, all current goes to the ground via short circuit, not the coil.

Anyway, the problem is somewhere in the chamber. This should be checked when EY is moved to the H1 position, most likely an offending cable should be replaced.

One of the reed switches is still stuck, despite a previous report that it was somehow magically unstuck: https://services.ligo-wa.caltech.edu/integrationissues/show_bug.cgi?id=2

When in "open" position both of the switches are closed. When "closed" one of the switch opens.