I went and tried to reflow the solder on the connections between the 4 wiring harnesses and the power PCB board, and just for good measure I tried to reflow the solder on the bridge rectifier. There was no effect in getting the machine to work correctly, it just does the same things as before.
However, one interesting thing I noticed is now, when I try to test continuity over the F2 fuse clips after removing the fuse, it no longer shows it as continuous.