Impinger II – 1100-000-A Series (SN 2038615 & Below) Service Manual –Int’l 13
under “Oven will not heat” can cause
intermittent failure.
Power supply Check incoming power supply, If no voltage is
present, check circuit breakers.
Fan switch With power off, Check continuity between
switch terminals. Replace as needed.
Speed adjustment
potentiometer This is a 0 to 10K ohm, 1 turn potentiometer.
With power off, remove the black and white
pot. leads from the motor control board at
terminals P1 and P2. Place the meter leads on
the black and white pot. leads. Rotating the
pot. slowly, from low to high, the meter reading
should show an even transition from 0 to 10K
ohms ± 5%. There should be no dead or open
spots throughout the rotation of the
potentiometer. Check both pot. leads to
ground. There should be no continuity to
ground. If any of the above checks fail, replace
the potentiometer.
DC motor control board Check for supply voltage input to the control
board at terminals L1 and L2. If voltage is not
present, check wiring back to the oven fan
switch. If supply voltage is present, check both
fuses on control board (8A line and 1A
armature). Check the DC voltage output at
terminals A+ and A-. If there is power in to the
control board but no power at A+ and A-, check
the following:
Hall effect sensor Disconnect the Hall effect sensor from the DC
motor control board. If the motor begins to run,
replace the Hall effect sensor.
DC motor control board If, after disconnecting the Hall effect sensor,
the motor is still not running, check for DC
voltage from terminals A+ and A-. If there is no
DC voltage, replace the DC motor control
board.
Circuit breaker If there is DC voltage output from the DC motor
control board, but the motor is still not running,
check the 0.4 Amp circuit breaker. Disconnect
wires from the circuit breaker and check for
continuity through the circuit breaker. Reset
circuit breaker or replace as needed.
Conveyor gearmotor Check the leads to the motor for evidence of
any shorts or opens, and each lead to ground.
If the motor fails the above tests, replace
motor. Rotate motor shaft to determine if there
is a locked rotor or a locked gearbox (use care
so that magnet and sensor are not damaged).
Check motor brushes for damage or excessive
wear. Replace brushes if needed. Replace
motor if needed. Also check to be sure that the
conveyor drive coupling is tight and properly
engaged to the conveyor shaft.
Conveyor will not run
Conveyor Check for any mechanical misalignment. Also,
check for worn bearings. A conveyor belt that is
too tight may cause excessive bearing wear
and sometimes, irregular speed.
Conveyor speed unsteady Power supply Check power supply at the DC motor control
board for supply voltage at terminals L1 and
L2. Supply voltage should be steady.