We always need many people to check several checking points to align the filter cavity. Also, the channels for monitoring video signals from the end room were not enough(two channels were working at that time).

This means: (1) camera is not enough   (2) channels are not enough

• For the camera, we set up a new camera to take real-time video inside PR chamber. By using this camera, we could check the overlap of injection/reflection beam.
• For the not enough channels, we found two cables(actually is fiber) were broken from west-south corner to control area(we can also call it 'short part' of fiber). We replaced them(Broken fibers are 1-13 and 1-14. 1-13 was replaced with a working fiber and the label was changed as well. Now the 3-11 short part is broken). Then we found one of the channels of board1 was broken after one-day work. We changed it to a good channel later.

In the end, we have four real-time videos on the screen and an additional one (first target) which can be monitored after we switch from channel A to channel B. The organization of four videos are as follows

 The connection situation at the end room is shown in the attached figure 1 and 2.