Fil, Dave:
Fil tested the corner station ITMY, ITMX HWWDs by disconnecting one of the satellite amp input connectors for a few seconds on each. The HWWDs went into LED-low-current mode (8) as expected.
We performed this test because over the past week ITMY and ETMX HWWDs have been very quiet, whereas ITMX and ETMY remain noisy. I cannot find any correlation in the main mass top drives signals and these quiet times.