Make sure to first disconnect the panel from the power feeds and then disconnect all monitoring devices from the monitor jack(s), if applicable. Then, using a Volt/Ohm meter, check for a normally open conditions among the BATT, S.GRD and RTN terminals.

If continuity (0 Ohms) is indicated between any of these terminals, a short exists either on the backplane bus or on one or more of the DSX modules plugged into the chassis. If a short is indicated, remove modules one by one to find the faulty module or panel fault.