Hi Tim
going by the poor quality the connectors use in my "mini lathe" resulting in high resistance connections
its possible the E-stop & power switch was damaged by the heat from poor connections
do the switch wires show signs of head damage ??
the question is did faulty e-stop switch & power switch cause damage to the laser cutters power supplies and / or laser power supplies ??
or the over current taken by a faulty power supplies and / or laser power supply damage the switches ??
I would replace the damaged switch & blown fuse then disconnect the mains supply from the laser power supply
and then test the controls power supply on its own
depending on the result ,then test the laser tubes power supply on its own
John