I think if the magnet fell off, we would see high DC signal, and not 0 as we do now. I suspect satellite box or PD readout board/cabling. I am looking into this, tester box is connected to ITMY sat. box for now. I will restore the suspension later in the evening.

Suspension has now been restored. With combination of multimeter, octopus cable and tester box, the problem is consistent with being in the readout board in 1X5/1X6 or the cable routing the signals there from the sat. box.

• Tester box hooked up to sat box ---> UL coil still shows 0 in CDS.
• Tester box hooked up to sat box ---> Mon D-sub on sat box shows expected voltages on DMM. So tester box LEDs are being powered and seem to work.
• Sat box re-connected to test mass ---> Mon D-sub on sat box shows expected voltages on DMM. So OSEM LEDs are being powered and seem to work.
• Sat box remains connected to TM ---> Front panel LEMO monitor points on readout board shows 0 for UL channel, other channels are okay.