Tuesday, June 08, 2021, 08:25: IV4 open. Optics set minus TPS:CB2. Shows as green 'on', set to 500V, however read back shows as 0 V.

Wednesday, June 09, 2021, 08:37: HV off. Attempts made to restart TPS:CB2 unsuccessful. Controls notified.

Wednesday, June 09, 2021, 11:49: Card replaced by controls. Verified "Ok"  in " LB Mode": RDVOL, RDCUR, RDDAC all similar. Operational again.