Lincoln 1922 Switch, Main Power, WITH POWER OFF Check continuity between switch, needed, follows

	Switch, Main Power	WITH POWER OFF: Check continuity between switch
		terminals. Replace switch as needed.
	Control transformer	Check for supply voltage to the primary of the control
		transformer. If no voltage is present, trace wiring back
		to the oven power relay. If voltage is present, check for
		24 VAC at the transformer secondary. If there is
		primary voltage but no secondary voltage, replace
		control transformer.
	Air pressure switch	Check for 208/240VAC to the air pressure switch. If no
		voltage is present, trace wiring back to main power
		switch. This normally open switch should close when
		the main fan is activated. Refer to the “Removal and
		installation” section for proper adjustment. Replace as
		needed.
	Switch, Infrared heater	Check for 208/240VAC to the Infrared heater switch. If
		no voltage is present, trace wiring back to the air
		pressure switch. WITH POWER OFF: Check continuity
		between switch terminals. Replace switch as needed.
	Conveyor motor	Check for supply voltage to the conveyor motor. If no
		voltage is present, trace wiring back to the primary of
		the control transformer. If voltage is present and the
		motor will not run, check the motor windings for opens
		or shorts.
		WITH POWER OFF: Check the motor windings as
		follows:
		Grey to black - 236 ohms	approx.
		Grey to brown - 236 ohms	approx.
		Brown to black - 472 ohms	approx.
		If any of the above fails, replace conveyor motor.
	Capacitor, conveyor motor	Check for shorts or grounds. Replace capacitor as
		needed.
		WARNING: Capacitor has a stored charge, discharge
		before testing.
	Switch, conveyor reversing	Check continuity between switch terminals. Replace
		switch as needed.
	Oven control	If there is supply voltage to the motor, and the motor,
		motor capacitor, and reversing switch check good,
		replace the oven control.
Conveyor motor runs, but there	Oven control	Check for output voltage from oven control to hall effect
is no speed display		sensor (sensor is located in conveyor motor). Measure
		voltage at the motor connector, red wire and yellow
		wire. Voltage should be approx. 10VDC. If no voltage is
		present, trace wiring back to oven control. If there is no
		voltage present at the oven control, replace the oven
		control.
	Conveyor motor	If there is voltage supplied to the hall effect sensor,
		check for a frequency output from the hall effect
		sensor. Measure frequency across the yellow and white
		wires at the motor connector. Frequency reading
		should be approx. 25 – 100 Hz. If these readings are
		not achieved, replace conveyor motor. If the readings
		are achieved, proceed.
	Oven control	If the hall effect sensor readings are correct, but there
		is no speed indicated on the display, replace the oven
		control.

DTF – 1920 Series Service Manual 9