One technique to use looking for a short is to apply some current limited supply and measure the voltage drop around the circuits, pcbs etc etc.
The current needs to be lowish and non-damaging as you will need to leave it connected for a while, you can either use a current source ( be sure to set the voltage limit to something sensible
) or probably better, a normal PSU / battery with a suitable series resistor. You need to be able to measure the voltage drop along wires and traces and the limitations are down to how much current, resistance of wires / traces (m Ohms) and your voltmeter sensitivity. A 6+ digit meter makes this easy even with a small currents but I imagine your 585 could pass a bit more current!
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