[Ohishi, Fujii, Hasegawa, Michimura]

We roughly adjusted the ETMX alignment so that the beam is reflected back into the BS direction.

What we did:
 1. Removed the EXA DC PD and its cables and pedestal from EXA chamber (see, also, klog #967).

 2. Before removal, I changed the PD (Thorlabs PDA100A) gain setting to 20dB. With this gain setting, the EXA_PDA1 showed ~1300 counts at maximum, which correspond to 0.4 mW. Still, the power seems too low. But we confirmed that the beam is likely to be direct beam from PR3 (see klog #972).

 3. Adjusted the ETMX alignment in pitch and yaw. During the adjustment, coils seemed to hit the magnets, so we had to move the position of the coils. We also had to bend the suspension so that the IM don't hit the damping magnets.

 4. Adjusting was done by looking at the Xarm GV window close to EXA. The reflected beam was centered at the window with some scattering at the edge of the window. The scattering could be seen by the IR viewer. We believe that we have done the rough alignment in roughly +/- 1 mrad.

 5. Removed everything other than ETMX for evacuation.

 6. Centered the oplev beam on QPD.

 7. Found that the coils don't work (kick by coils didn't affect the oplev output).

 8. Checked the cabling and found that the hand-made Dsub 15pin-9pin connector was broken. We repaired it by soldering. We also taped the connetor and tightened the cable so that it won't break again.

 9. We also need to turn the switch off and on again because the High Power Coil Driver used for ETMX suspension was tripped.

Next:
 1. Sweep ETMX to see the beam at BS.
 2. The range of the sweep might be limited by the coil driver trip. We need investigation on the High Power Coil Driver.
 3. Replace the Dsub 15pin-9pin connector to more reliable one.