strange that all 3 blow their fuse.
do they energies first before blowing the fuses?
did they lock on before they stopped working?
check the diodes on the coils
check that the coils haven burned out

if they are locking on when you power up the machine (with new fuses) then check that all the boards are grounded properly.
might be a bad DC ground (pin 6 on the pop bumper driver boards which is used for the pop bumper switch and electronic components on the pop bumper driver board ) i am looking at another system 80b schematic and from the schematic it looks like the ground that goes to pin 6 on each driver board is daisy chained.
The other ground that is used to ground the coils has an individual wire that goes to each bumper driver board (pin 2) if that make sense

so pin 6 logic ground for pop bumper switch and pop bumper driver board components is daisy chained
and pin 2 coil ground is not daisy chained