Along with the plan in ELOG 14744, the ISC PD interface and the whitening filter board have been modificed. The ISC PD I/Fs were restored to the crate and the cables were connected. The whitening filteres are still on the electronics bench for some more tests before being returned to the crate.

The updated schematics were uploaded as https://dcc.ligo.org/D1900318 and https://dcc.ligo.org/D1900319

- Modification of the ISC PD interface: Jumpers between DIN96 P1 and P2. Replace all AD797s with OP27. In fact only I/F #1 (the left most)  had total 12 AD797 but the other units already had OP27s.

- Modification of the whitening filter: Jumpers between DIN96 P1 and P2.