Mathey Dearman MiniMag XM - Manual (Page 14)

Symptom What to Do Corrective Action
Drive
Motor (1)
does not
rotate
Remove the Fuse from the Motor Control Box (13).
Place a Lead of the volt/ohm Meter on each side of
the Fuse and check the Fuse for continuity.
If the volt/ohm Meter measures
0 ohms, replace 3amp Fuse (19).
Plug the Motor Control Box (13) into a 110-VAC
outlet. Move the Forward and Reverse Switch (F) to
the Forward or Reverse Position. Turn the Rheostat
(G) clockwise until it stops. The voltage across the 2
pins of the Beldon Cord should be 80 - 90 vdc
If the Motor Control Box has little
or no output voltage and the Fuse is
not blown, send the Motor Control
Box to the Mathey Dearman for
repair.
Disconnect the 2 Connecting Lugs between the
Drive Motor and the Beldon Cord 20). Check the
voltage across the 2 lugs of the Beldon Cord ((20).
Caution: Care should taken not to pull the electrical
lead out of the motor
If there is no continuity of one or
both Electrical Leads and it cannot
be repaired without taking apart the
Motor, replace the Motor.
Hook a volt-ohm meter between 1 of the Leads of
the 90-volt Leads of the Motor Control Box and one
of the Leads of the Motor. Plug the Motor Control
Box into a 110 VAC Electrical Outlet. Turn the
Forward and Reverse Switch (F) to the forward or
reverse position. Turn the Rheostat (G) clockwise
until it stops.
Note: If you do not get a reading with the ampere
meter move the Forward and Reverse Switch (F) in
the opposite position.
If there is carbon built up in the
Motor, you will see rapid
fluctuation of the Ampere Meter.
Remove the Rectangular Plate from
the Motor and use clean dry air to
blow the carbon dust out of the
Motor.
Warning: Use a Face Shield and
Particle Mask, when using air to
blow the carbon out of the Motor.
Note: Run a new Motor run for 10
minutes, before checking with
ampere meter. Remove the
Rectangular Inspection Plate from
the back of the Motor and inspect
the Motor for carbon dust build up.
Use clean dry air to remove the
carbon dust.
Remove the Motor from the Transmission. Stick a
common Screwdriver into the Slot of the
Transmission Shaft and turn it clockwise or counter
clockwise.
If Transmission turns freely place a
Washer between the Motor Flange
and the inner wall of the
Mini‘Mag’
body. Follow the
instruction for “Installation of the
Drive Motor”.
If the Transmission turns freely
after the Screws in the Mounting
Blocks are loosened, follow the
instructions for “Adjusting the
MagnaCutXM
Tracking.”
Remove the Rectangular Inspection Plate from the
back of the Motor and inspect the Armature for
flaking of the lacquer, which will indicate the Motor
has been severely overheated.
Replace the Motor.
Remove the both Brushes from the Motor. Check the
Brush for chipping and measure the length of the
Brush.
If the Brush is chipped or the Brush
measures shorter than ¼” replace
the Brush.
Drive Motor
is grinding
or is not
rotating
correctly
Remove the Rectangular Inspection Plate from the
back of the Motor and inspect the Commutator for
Arc Marks. If the Commutator of the Motor has
Arc Marks, replace the motor.
Note: Do not replace the Brushes
in a Motor having an Arc
Commutator as they will have a
short life span.
Check the Brush for chipping and measure the
length of the Brush. If the Brush is chipped or the Brush
measures shorter than ¼” replace
the brush.