Got handed this one, another company couldn't fix it.
They replaced the Wiper motor assembly, which contains the sensor among
other things.
It's obvious the motor isn't turning, because the waste ink tubes are empty.
Also, I put a mark on one of the gears in the assembly and it isn't moving.
Traced back to the main board, the input voltage to that board is good.
5v & 12 v, but when I check the motor output, nothing.
The old wiper assembly, the top gear, a one way gear, has some wiggle in it
and I wonder if that caused it too much torque on the assembly, putting too
much strain on the motor, which popped the driver(s) on the main control
board.
I know pretty much nothing about these Mutoh printers, but I was able to
find a service/parts manual.

Anyone else service these?

Photo is of the old unit.

PXL_20220504_161528615.jpg