Working on a Dukane MCS350 intercom system for the first time. Upon plugging in the console it (used to) got power, but displayed a "COM FAILURE" error. With the status switch in position B on the digital card, no LED's are lit. Clearly not talking to the CCU. Re-terminated everything, tried a different cable, no change.
So, I tried reversing the polarity on the data pair. Now the console won't power up at all, even with that pair put back to its original state. I've checked the fuse for that ACC and the main system fuse on the analog card, as well as the power supply fuses to no avail. Double checked the wiring diagram in the ACC manual. Pin 1 Serial -, pin 2 serial +, pin 3 power +, pin 4 audio, pin 5 audio, pin 6 power -. Even reversed the order in case the jack I was working with was labeled upside down or something.
No life from the console at all. Any suggestions? Feel like I'm going crazy
