Yuhang, Eleonora

We removed the broken card from the AI module (see elog #2093) and we found that at least 3 opamp AD8622 were burnt. (see pic 1,2)

The evidently broken opamps are: (see pic 3)

CH2 -> Oplev PR X

CH3 -> Oplev PR SUM

CH6 -> Oplev BS SUM

CH3 and CH6 are the most damaged. They corresponds to the SUM of oplev PSD for PR and BS. We remark that this two PSD uses the same power supply. 

We also remark that PR PSD is not working fine anymore (in particular channel Y and SUM).

We asked Miyakawa-san who said they have never had a similar problem in KAGRA.