DOB 1300-1556 | X3-45 Commuter PA-1648 Maintenance Manual Section 06 revised release October 2021
Isolate the front from the rear
Take one of the termination resistors in the MAIN POWER COMPARTMENT.
Disconnect C1 and connect the termination resistor to C1 pin housing.
If all the front modules respond normally, the short circuit is in the rear portion.
Isolate the evaporator module from the network
Disconnect C100.
No need to connect a termination resistor there since C100 is a stub connection.
If the short circuit problem is in the evaporator panel, all modules except AE54 will respond normally.