Maytag UMV1152CA Checkout Procedure: Fuse, Troubleshooting Procedures, Symptom, Cause, Correction

Troubleshooting Procedures

!WARNING

To avoid risk of electrical shock, personal injury, or death, disconnect power to microwave oven and discharge the high-voltage capacitor before servicing, unless testing requires power.

Symptom		Cause	Correction
Microwave oven fan motor	1.	Door sensing switch loose connector.	Check connector and wiring of
engages when power cord is	2.	Door sensing switch loose wires.	door sensing switch.
plugged in.
Microwave oven does not operate,	1.	Check input voltage.	Make sure house outlet works.
oven not in standby mode when	2.	Defective PCB assembly.	Replace PCB assembly.
power cord is plugged in.
Microwave oven emitting a loud,	1.	Fan and/or fan motor loose.	Check fan and/or fan motor.
buzzing noise.	2.	High voltage transformer loose.	Check high voltage transformer.
	3.	High voltage diode shorted.	Replace high voltage diode.
Microwave oven turntable motor	1.	Turntable motor wiring loose/open.	Check wiring of turntable motor.
does not rotate.	2.	Defective turntable motor.	Replace turntable motor.
Microwave oven stops during	1.	Open or loose wiring of primary	Adjust door and latch switches.
cooking operation.		interlock switch.	Allow microwave oven to cool to
	2.	Open thermal (magnetron) cutout.	determine if magnetron TCO is
			defective. Replace if necessary.
Microwave oven emits sparks	1.	Metallic ware or cooking dishes	Do not use cookware with
when cooking.		touching on the oven wall.	metallic trimming or gold/silver
	2.	Ceramic ware trimmed with gold or	powder.
		silver powder.
Microwave oven cooks unevenly.	1.	Uneven intensity of microwave due	Cover food with plastic wrap or
		to microwave characteristics.	cover food with a lid.
	2.	Microwave cavity dirty.	Clean microwave cavity.
Microwave oven turntable emits	1.	Turntable motor loose.	Tighten screws securing motor.
noise when operating.	2.	Turntable motor defective.	Replace turntable motor.

Checkout Procedure: Fuse

PROBLEM	CAUSE
Fuse blows immediately after door is closed.	Improper operation of the primary interlock and secondary
Fuse blows immediately after door is opened.	interlock switches and/or interlock monitor switch.
Fuse blows when door is closed and START	Malfunction of high voltage transformer; high voltage capacitor
key is touched.	including diode, magnetron, blower motor or circuit board.

NOTES: Replace blown fuse with 20 Amp fuse.

If the fuse is blown due to an improper switch operation, replace all interlock switches, PCB Ass’y and the fuse simultaneously, and ensure they are connected properly.

Check for microwave energy leakage after replacing interlock and monitor switches.

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