0.2Ω short circuit resistance is pretty low, in such cases the short circuit test usually shows nothing, because the resistance is too low.
It is more than likely shorted one of the filter capacitors.
Remove inductors PL101, PL202 and jumpers PJP302, PJP500, PJP700, PJP701, PJP800 and PJP1100 one by one, and during this measure resistance to ground on power rail "B+" (pins 1, 2, 3 of PQ102). If the resistance on power rail "B+" jumps to high value, stop removing the further components.
It is more than likely shorted one of the filter capacitors.
Remove inductors PL101, PL202 and jumpers PJP302, PJP500, PJP700, PJP701, PJP800 and PJP1100 one by one, and during this measure resistance to ground on power rail "B+" (pins 1, 2, 3 of PQ102). If the resistance on power rail "B+" jumps to high value, stop removing the further components.