Troubleshooting-Machine Does Not Start - Allpro 400E Operations Manual & Parts List

TROUBLESHOOTING- Machine does not start.
CAUSE
Control Settings
Power Source
Fuse
Thermal Overload
Pressure Control Assembly
(Board)
Sensor
Pressure Control
Knob (Potentiometer)
Motor
Pressure
Calibration
Pressure Control Assembly
(Board)
14
STEP 1: Ensure that the ON-Off toggle switch is in the "ON" position and that the
Pressure Control Knob is fully CW (maximum pressure). Also check that
the unit is plugged in.
STEP 2: Remove the electrical cover on the bottom of the machine. Check if the
green power light on the board is lit. If the light is "OFF", proceed to
Step 3. If the light is "ON", go to Step 7.
STEP 3: Use a multimeter to check for 110 volts VAC across the L1 and L2
terminals on the board. If there is no voltage at these leads, there is
no power to the unit. Check power source (outlet, breakers, extension
cord and power cord).
STEP 4: If the machine has power and the green light is "OFF", test the fuse for
continuity or replace with a new fuse.
STEP 5: If the fuse is okay, disconnect the two red motor leads (S1 & S2) and
test for continuity between the two leads. Continuity shows that the
motor's thermal coupler has not tripped. No continuity means that the
thermal coupler has opened due to excessive motor heat. If the motor
is still hot to touch, allow to cool and retest. If the motor is cool and there
is no continuity on the red leads, contact your local Leeson repair facility
to repair/ replace the thermal coupler.
STEP 6: If all checks out fine in Steps 1 through 5 and the green light is still out,
the pressure control assembly is defective and must be replaced.
STEP 7: If the green light is "ON", the power source, fuse and thermal coupler are
okay. Plug another sensor into the board. If the unit starts, the sensor was
faulty and must be replaced. When a replacement sensor is not available,
use a multimeter to test the resistance between the BLACK and RED wires
on the sensor lead. The resistance should be approximately 1.5-3.5 kohms.
A faulty sensor usually reads zero resistance (open).
STEP 8: With the machine still "OFF", remove the potentiometer lead from the
board and read the resistance between the red and black wires. This
must be 8 - 12 kohms. If outside this range, replace the potentiometer.
NOTE: A bad POT will usually show no resistance (open).
STEP 10: Remove the two black motor leads (A1 & A2) and test for continuity
between them. Continuity is an indication that the motor is sound. The
lack of continuity, points to a problem in the motor. If there is no
continuity on these two leads, check the motor brushes. Ensure that
the brushes are evenly worn and make solid contact with motor
commutator. Replace the brushes if they are less than 3/8" long. If the
brushes are okay, replace the motor.
STEP 11: Calibrate the pressure control assembly in accordance with the
instructions on page 15.
STEP 12: If the unit fails to calibrate and all components in Steps 1-10 test okay,
the pressure control assembly needs to be replaced.
SOLUTION