As you speak about the power output, and that means ALL chassis on one speaker don't work?

Does the speaker wake up - out of standby- or not when you test it?
Do you type it as a master or not?

The comms board is the little board where the comms cable and digital audio get connected.

It react to the MSR/processor commands like switch the DSP on or off, volume...

The second thing is that the SPDIF signal get transferred to the processor board via the flat cable what is shown in your pictures what you posted in that thread.

Robert


800v3/218/271/8k.2/5k5s smile /5kC/DSP3200/Reviver/
TT-ELP/Graham Slee Revelation/Trinnov Altitude 32/OPPO 205
__Ayon/HB/Shunyata/Miltzow -- power cables,
__Ayon/Jungson/Miltzow --analog, Miltzow-- digital,
__Vortex/WMA ,