Jason, Kiwamu,

PR3 oplev has not been properly behaving. We don't know when it ran into the issue. We will take a close look in the next maintenance Tuesday as we are suspecting a bad QPD and/or bad electronics.

[Cross-coupling issue]

Currently the symptoms are that:

• Moving the PR3 suspension in pitch shows a large cross coupling to yaw (more than 50%) and the same is true when moving the suspension in yaw.
• When each segment receives equal amount of light, segment 2 seems to respond much lesser than everyone else to the suspension angular motion.

At this point, we are not sure if this is due to a bad QPD segment or some kind of electrtonics issue.

[Dip switch confusion]

Independently of the cross-coupling issue, we found that a dip switch for the seg3 whitening filter had been set differently than the rest of three segments. We thought this would fix the cross coupling issue at the begginig, but switching it to the position that everyone else have been did not solve the issue because the cross-coupling behavior which is described above arose in turn. It is unclear how long the dip swtich has been in this configuration. Note that the last maintenance activity on PR3 was performed almost a month ago (on 7th of this April, alog 17722)