Lincoln 1400 Series service manual Models, 1474-1475-1476

	DC Motor Control Board	Check for 120 VAC input to the control board at
		terminals L1 and L2. If not present, check the oven
		fan switch and wiring back to 3 amp fuse and then
		back to power source if necessary. If 120 VAC is
		present at L1 and L2, check both fuses on control
		board (4A line) and (1A armature), check the VDC
		output at terminals A+ and A-. If 120 VAC is present
		at terminals L1 and L2, and DC voltage is present A+
		and A-, but motor does not run, check gear motor as
		follows.
	Conveyor Gear Motor	If DC voltage is present at A+ and A-and the motor
		does not run, first check the mini breaker and then the
		conveyor. Refer to the next possible cause. 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. From the top of the motor,
		rotate motor shaft to determine if there is a locked
		rotor or a locked gear box (use care so magnet and
		the H.S. board are not damaged). Replace as needed.
	Conveyor	Check for any mechanical mis-alignment . Also check
		for worn bearings. A conveyor belt that is over
		tightened may cause excessive bearing wear and
		sometimes, irregular speed.
Conveyor speed	Power Supply	Check power supply at the DC control board for the
varying or intermittent		120 VAC at board terminals L1 and L2
	D.C. Motor Control Board	Place the test meter probes on terminals A+ and A- .
		(With speed potentiometer set to maximum speed (
		Approx. 2 min.) The meter reading should be
		approximately 100 VDC (±3%). The board output is
		steady. If the board voltage output is unsteady beyond
		limits (±3%) then the board is probably bad. Always
		check the speed pot. , be sure it is okay before
		changing a board. This test is not always 100%
		accurate as this test is not performed at operating
		speeds. However, this test is the best method
		currently available.
	DC Gearmotor	If the DC control board is steady then the problem
		may be the motor or gearbox. Check the brushes in
		the motor for excessive arching and/or unusual wear.
		Check the motor and gearbox from instruction located
		on page 14 under "possible cause" Listing "conveyor
		gear motor."
	Magnet	Check to insure that the magnet (cemented to shaft of
		conveyor drive motor) has not been damaged, or
		come loose from motor shaft. Replace as needed.
	Hall Effect Sensor	Check for any physical damage to Hall Effect Sensor
		(mounted on conveyor drive motor Check all wiring
		and connections for damage. Check all connections
		for tightness or proper location and check all wiring for
		visible damage. Replace as needed. Connect new
		Hall Effect to system and check for steady operation.
MODELS 1456 - 1457-	1474-1475-1476
Oven will not heat	Gas Supply	Check for adequate gas supply to oven.
	Manual Gas Shut-Off Valve	Check to see that manual shut-off valve is open.
	Fan Switch	Check to see that the fan switch is on.
	Main Oven Fan	Check if main oven fan is operating. If not, refer to
		"Oven fan will not run."
	Air Pressure Switch	Check for supply voltage on both sides of switch. If
		voltage present on one side only, check for air tube
		blockage or misalignment, adjust air switch. Replace
		as needed.

14 Impinger I – 1400 Series Advantage Service Manual - Dom & Int’l