Sigma 1457, 1433-000-E, 1456, 1434-000-E service manual With Power on and Thermocouple, Belt JAM

	Oven control	If the thermocouple checks good, but the oven control
		display indicates that there is a thermocouple failure,
		replace the oven control. If the oven control indicates a
		temperature reading, but the oven will not heat, proceed.
	Thermocouple	WITH POWER ON AND THERMOCOUPLE
		ATTACHED TO THE OVEN CONTROL: Measure the
		DC millivolt output of the thermocouple. Refer to the
		thermocouple chart (located in the “Removal” section of
		the manual) for proper millivolt readings. If these
		readings are not achieved, replace thermocouple.
	Oven control	If the thermocouple checks good, but there is no supply
		voltage output to the temperature regulation valve,
		replace the oven control. If there is supply voltage output
		to the temperature regulation valve, proceed.
	Temperature regulation valve	Check for supply voltage to the temperature regulation
		valve. If voltage is present, listen for valve to open and
		close. Also check for opens or shorts in the operating
		coil. Replace temperature regulation valve as needed.
Intermittent heating	Thermal/overload of main fan	The main fan motor and burner blower motor are
	and burner blower motor	equipped with internal thermal protection and will cease
		to operate if overheating occurs. As the motors overheat
		and cool, this will cause the heating system to cycle on
		and off intermittently. Improper ventilation or lack of
		preventive maintenance may cause this problem. Also
		most of the problems listed under “Oven will not heat”
		can cause intermittent failure.
Conveyor will not run	Incoming power supply	Check circuit breaker, reset if required. Check power
		plug to be sure it is firmly in receptacle. Measure
		incoming power, call power co. if required.
	Fuse, 10 Amp	Check, replace if necessary.
	Fuse holder	Check, replace if necessary.
	Switch, oven power	Check for line voltage supplied to switch. If no voltage
		is present, trace wiring back to fuse holder. Check
		continuity between switch terminals. Replace switch as
		needed.
	Control transformer	Check for supply voltage to primary of control
		transformer. If no voltage is present, trace wiring back to
		oven power switch. If voltage is present, check for
		24VAC at transformer secondary. If there is primary
		voltage, but no secondary voltage, replace control
		transformer.
	Conveyor motor	Check for supply voltage to the conveyor motor at
		terminal #6 to neutral. If no voltage is present, trace
		wiring back to oven power switch. If voltage is present,
		but the motor will not run, check the motor windings for
		opens or shorts. If any of the above checks fail, 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 voltage supplied to the motor, and the motor
		capacitor and reversing switch check good, replace the
		oven control.
Conveyor motor runs,	NOTE: Display will indicate
but there is no speed	“BELT JAM”
display
	Oven control	Check for output voltage from oven control to hall effect

10 Impinger I – Adv Digital – Gas Service Manual – International