I have a Pi3 with Pro XLR DAC. Had it or years. It has been connected to a Behringer Truth 2092 powered subwoofer and a pair of M-Audio BX5a speakers. The DAC feeds the sub, which has hi pass outputs for the monitors. All wiring are XLR cables. This arrangement has worked well for several years.
This week I did some tidying up, which involved moving and reassembling the system.
Once complete the Pi will not power up if connected to the sub. If I connect it directly to the BX5s it works fine. As soon as I connect one DAC output to the input of the sub the Pi shuts off. All lights dark. Unplug the XLR cable and the Pi comes back up.
I have second identical sub in another room. So I swapped the subs. Same thing.
Any guesses as to why this would happen now?