About the second iris's camera, SHG and infrared beam

Today I tried to find infrared beam again. But I found two things.

Firstly, I checked the camera for the second iris. I brought two cameras and one cable around the second iris back. We have a PR's camera, so I used it to check. The method is to replace one thing at a time. In this way, we can diagnose the replaced component. I found the cable is fine but two cameras are broken.
Broken camera 1: SONY NO.92980
Broken camera 2:SONY NO.161274

Secondly, I found the drifting of SHG is really serious.(with the driven voltage set around 50V). Within only 30 min or less, the power decreased from 50mW to 30mW and final 10mW. The measurement point is ahead of filter cavity's EOM.

Finally, I took a picture of the beam which is sent to our filter cavity. You can see from the attached photo. The beam is a combination of a large bright beam point and a small weak point. I cannot make it a rough circle by just adjusting the turing mirror or local control offset.