Maytag ACM0860AS, ACM0720AW, ACM0860AB, ACM0860AC, ACM0860AW Service Manual

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Service

This manual is to be used by qualified appliance technicians only. Maytag does not assume any responsibility for property damage or personal injury for improper service procedures done by an unqualified person.

2001-2003 Countertop

This Base Manual covers general information

Domestic Microwave Ovens

This manual includes, but is

not limited to the following:

ACM0720AB ACM0720AW ACM0860AB ACM0860AC ACM0860AS ACM0860AW ACM1120AB ACM1120AS ACM1120AW ACM1420AB ACM1420AW ACM1460AB ACM1460AC ACM1460AW ACM2160AB ACM2160AC ACM2160AS ACM2160AW MMC5086AAB MMC5086AAQ MMC5086AAS MMC5086AAW UMC1061AAB UMC1061AAW

16026268

Replaces 16021670

June 2005

Important Information

Pride and workmanship go into every product to provide our customers with quality products. It is possible, however, that during its lifetime a product may require service. Products should be serviced only by a qualified service technician who is familiar with the safety procedures required in the repair and who is equipped with the proper tools, parts, testing instruments and the appropriate service manual. REVIEW ALL SERVICE INFORMATION IN THE

APPROPRIATE SERVICE MANUAL BEFORE BEGINNING REPAIRS.

Important Notices for Consumers and Servicers

To avoid risk of serious injury or death, repairs should not be attempted by an unauthorized personal, dangerous conditions (such as exposure to electrical shock) may result.

Maytag will not be responsible for any injury or property damage from improper service procedures. If performing service on your own product, assume responsibility for any personal injury or property damage which may result.

To locate an authorized servicer, please consult your telephone book or the dealer from whom you purchased this product. For further assistance, please contact:

WARNING

CAUTION

Customer Service Support Center

CAIR Center

Web Site Telephone Number

WWW.AMANA.COM................................................ 1-800-843-0304

WWW.JENNAIR.COM ............................................. 1-800-536-6247

WWW.MAYTAG.COM ............................................. 1-800-688-9900

CAIR Center in Canada ........................................... 1-800-688-2002

Amana Canada Product ........................................... 1-866-587-2002

Recognize Safety Symbols, Words, and Labels

DANGER!

DANGER—Immediate hazards which WILL result in severe personal injury or death.

WARNING!

WARNING—Hazards or unsafe practices which COULD result in severe personal injury or death.

CAUTION!

CAUTION—Hazards or unsafe practices which COULD result in minor personal injury or product or property

damage.

Table of Contents

Important Information ................................................... 2

Important Product Information...................................... 4

Important Safety Information ........................................ 5

Microwave Leakage Testing ......................................... 6

Specification Information .............................................. 7

General Information

Placement of the Oven ............................................. 9

Location of Model Number ........................................ 9

Model Identification ................................................... 9

Service ....................................................................... 9

Parts and Accessories .............................................. 9

Extended Service Plan .............................................. 9

Radio Interference..................................................... 9

Electrical Requirements ........................................... 10

Cleaning .................................................................. 10

Grounding Instructions ............................................ 10

Microwave Oven Description .................................... 11

Testing Procedures

Primary Interlock Switch Test ...................................12

Secondary Interlock Switch Test...............................12

Interlock Monitor Switch Test....................................12

Magnetron ................................................................ 12

High Voltage Diode ................................................... 13

High Voltage Transformer ..........................................13

Fan Motor ................................................................. 13

Turntable Motor .........................................................13

High Voltage Capacitor ............................................. 13

Humidity Sensor ....................................................... 13

Relay ........................................................................ 14

Oven Thermostat ......................................................14

Fuse ......................................................................... 14

Control Key Panel..................................................... 15

Troubleshooting Procedures ........................................16

Disassembly Procedures

Door Assembly ......................................................... 22

Door Disassembly .................................................... 22

Outer Case ............................................................... 23

Control Panel ............................................................23

P.C. Board ................................................................23

Control Key Panel..................................................... 24

Interlock Door Latch Switches ..................................24

High Voltage Capacitor ............................................. 25

Diode ........................................................................ 25

Transformer .............................................................. 26

Fuse ......................................................................... 26

Magnetron ................................................................ 26

Suction Guide / Fan Motor Assembly .......................26

Humidity Sensor–ACM1460A* and ACM2160A* ....... 27

Oven Thermostat ......................................................27

Light Socket .............................................................27

Turntable Motor........................................................ 27

Noise Filter .............................................................. 27

Wiring Diagrams And Schematics.............................. 28

Appendix A

Installation Instructions .......................................... A-2

Appendix B

Programming Instructions for

ACM0720A* and ACM1061A* .............................. B-2

Programming Instructions for

ACM1120A* and ACM1420A*............................. B-4

Programming Instructions for

ACM1460A* and ACM2160A* .............................. B-7

Programming Instructions for

ACM0860A* and MMC5086A* .......................... B-10

Appendix C

Cleaning Instructions .............................................. C-2

Important Product Information

WARNING

Precautions to be observed before and during servicing to avoid possible exposure to excessive microwave energy, or electrical shock disconnect power to oven.

WARNING

To avoid risk of electrical shock, injury, or death, make sure these grounding instructions are followed.

(A) Do not operate or allow oven to be operated with

door open.

(B) Make the following safety checks on all ovens to

be serviced before activating the magnetron or other microwave source, and make repairs as necessary:

• Interlock operation

• Proper door closing

• Seal and sealing surfaces (arcing, wear, and other damage)

• Damage to or loosening of hinges and latches

• Evidence of dropping or abuse

service test or inspection within the microwave generating compartments, check the magnetron, waveguide or transmission line, and cavity for proper alignment, integrity, and connections.

(D) Any failed or misadjusted components in the

interlock, monitor, door seal, and microwave generation and transmission systems shall be repaired, replaced or adjusted by procedures described in this manual before oven is released to the consumer.

(E) Check microwave leakage to verify compliance with

the federal performance standard should be performed on each oven prior to release to the consumer.

Grounding Instructions

WARNING

Do not remove grounding prong when installing grounded appliance in a home or business that does not have three wire grounding receptacle, under no condition is grounding prong to be cut off or removed. It is the personal responsibility of the consumer to contact a qualified electrician and have properly grounded three prong wall receptacle installed in accordance with appropriate electrical codes

Should a two prong adapter plug be required temporarily, it is the personal responsibility of the consumer to have it replaced with properly grounded three prong receptacle or the two prong adapter properly grounded by a qualified electrician in accordance with appropriate electrical codes.

Servicing of Grounded Products

The standard accepted color coding for grounding wires is GREEN or GREEN WITH YELLOW STRIPE. These ground leads are NOT to be used as current carrying conductors. It is extremely important that the technician replace any and all grounds prior to completion of the service call. Under no condition should ground wire be left off causing a potential hazard to technicians and consumer.

Wiring

Good service practice is to never route wiring over terminals and/or sharp edges. This applies to any wiring without regard to the circuit voltage. Wire insulation material and thickness is designed and regulated for electrical spacing purpose only, but cannot always be relied upon because of possible cuts and/or abrasions, which can occur during servicing.

Important Safety Information

CAUTION

Read the following information to avoid possible exposure to microwave radiation:

The basic design of the Maytag and Amana microwave oven makes it an inherently safe device to both use and service. However, there are some precautions which should be followed when servicing the microwave oven to maintain this safety. These are as follows:

1. Always operate the unit from an adequately grounded outlet. Do not operate on a two-wire extension cord.

2. Before servicing the unit (if unit is operable), perform the microwave leakage test.

3. The oven should never be operated if the door does not fit properly against the seal, the hinges or hinge bearings are damaged or broken; the choke is damaged, (pieces missing, etc.); or any other visible damage can be noted. Check the choke area to ensure that this area is clean and free of all foreign matter.

4. If the oven operates with the door open and produces microwave energy, take the following steps.

A. Tell the user not to operate the oven. B. Contact Maytag immediately.

5. Always have the oven disconnected when the outer case is removed except when making the "live" tests called for in the Service Manual. Do not reach into the equipment area while the unit is energized. Make all connections for the test and check them for tightness before plugging the cord into the outlet.

6. Always ground the capacitors on the magnetron filter box and H. V. Capacitor with an insulated-handle screwdriver before working in the high voltage area of the equipment compartment. Some types of failures will leave a charge in these capacitors and the discharge could cause a reflex action which could make you injure yourself.

7. In the area of the transformer, capacitor, diode, and magnetron there is HIGH VOLTAGE. When the unit is operating, keep this area clean and free of anything which could possibly cause an arc or ground, etc.

8. Do not for any reason defeat the interlock switches. There is no valid reason for this action at any time; nor will it be condoned by Maytag.

9. IMPORTANT: Before returning a microwave to a customer, check for proper switch interlock action. The primary and secondary switches MUST open when the door is actuated. The monitor switch MUST close at a 1/4 inch when the door is opened.

10.Before returning a microwave to a customer, verify the door spacing is reasonably uniform along the top, bottom, and sides, and that it measures 1/8 inch or less.

11. The microwave oven should never be operated with:

• Any components removed and/or bypassed.

• Any of the safety interlocks failing.

• Any of the seal surfaces failing, missing, or

damaged.

12.To ensure that the unit does not emit excessive microwave leakage and to meet the Department of Health Human Service guidelines, check the oven for microwave leakage using Narda Model 8100, 8200, Holaday HI1500, HI1501 or Simpson 380M leakage monitor as outlined in the instructions. The maximum leakage level allowed is 4mW/cm2.

13.If servicer encounters an emission reading over 4 mW/cm2, the servicer is to cease repair and contact the Maytag Service Department immediately for further direction. Maytag will contact the proper Government Agency upon verification of the test results.

Microwave Leakage Testing

WAR NI NG

Check for radiation leakage after servicing. Should the leakage be more than 4mW/cm2 inform Maytag immediately. After repairing or replacing any radiation safety device, keep a written record for future reference, as required by D.H.H.S. and HEW regulations. This requirement must be strictly observed. In addition, the leakage reading must be recorded on the service repair ticket while in the customer’s home.

Equipment

• Electromagnetic radiation monitor

• 600 cc glass beaker

Procedure For Measuring Radiation Leakage

Note before measuring -

• Do not exceed meter full scale deflection. Leak monitor should initially be set to the highest scale.

• To prevent false readings the test probe should be held by the grip portion of the handle only.

• The scan speed is equal to one inch per antenna revolution or one inch per second if antenna speed is unknown.

• Areas to be checked are all door seal areas and any venting parts.

• Leakage with the outer panel removed...4mW/cm2 or less.

• Leakage for fully assembled oven with door normally closed ...4mW/cm2 or less.

• Leakage for a fully assembly oven (before the latch switch (primary) is interrupted) while pulling the door ... 4mW/cm2 or less.

1 . Pour 275 ±15 cc (9 oz ±1/2 oz) of 20 ± 5°C

(68 ± 9°F) water in a beaker which is graduated to 600 cc and place the beaker in the center of oven.

2. Set the radiation monitor to 2450 MHz and use it

following the manufacturer’s recommended test procedure to assure correct results.

3. While measuring the leakage, always use the two

inch (5 cm) spacer supplied with the probe.

4. Press the start pad or turn on the timer and with the

magnetron oscillating, measure the leakage by holding the probe perpendicular to the surface being measured.

Measurement With the Outer Panel Removed

DANGER

Avoid contacting any high voltage components.

Whenever you replace the magnetron, measure for radiation leakage before the outer panel is installed and after all necessary components are replaced or adjusted. Special care should be taken in measuring around the magnetron.

Measurement With a Fully Assembled Oven

After all components including the outer panel are fully assembled, measure for radiation leakage around the door periphery, the door viewing window, the exhaust opening, and air inlet openings.

Record Keeping and Notification After Measurement

1. After any adjustment or repair to a microwave oven, a leakage reading must be taken. Record this leakage reading on the repair ticket even if it is zero.

2. A copy of the repair ticket and the microwave leakage reading should be kept by the repair facility.

Specification Information

Item Description

Model ACM1420A* ACM1460A* ACM2160A*

Power Requirement 120 Volts AC 60 Hz 1,500 Watts (13A) Single phase, 3 wire grounded Power Output 1100 Watts full microwave power (IEC705) Microwave Frequency 2,450 MHz Timer 0 ~ 99 min. 99 sec. Outside Dimensions 21 7/8” (W)

x 17 1/4” (H) x 12 5/8” (D)

Cavity Dimensions 14 3/4” (W)

x 15 15/16” (H)

x 9 7/8” (D) Net Weight 37 lbs. (approx.) 37 lbs. (approx.) 42 lbs. (approx.) Shipping Weight 40 lbs. (approx.) 40 lbs. (approx.) 46 lbs. (approx.) Control Complement Touch Control System

Clock: 1:00 - 12:59 Microwave Power for Variable Cooking Power Level HIGH ---------------------------------------------------------Full power throughout the cooking time 9 (Sauté) ------- approx. 90% of Full power, 8 (Reheat) ----------- approx. 80% 7 (Med.-High) ------------------- approx. 70%, 6 (Medium) ---------- approx. 60% 5 (Med.-Low) -------------------- approx. 50%, 4 (Defrost) ----------- approx. 40% 3 (Low) ---------------------------- approx. 30%, 2 (Simmer) ---------- approx. 20%

1 (Warm) ------------------------ approx. 10% Nameplate Location Front Accessories Owner’s manual & cooking guide

Glass Turntable

Rotating Ring This microwave oven is designed for household use only. It is not recommended for commercial purposes.

Item Description

Model UMC1061AA*

Power Requirement 120 Volts AC 60 Hz 1,000 Watts (8.5 A) Single phase, 3 wire grounded Power Output 700 Watts full microwave power (IEC705) Microwave Frequency 2,450 MHz Timer 0 ~ 99 min. 99 sec. Outside Dimensions 17 15/16” (W) x 11 3/16” (H) x 12 5/8” (D) Cavity Dimensions 12 3/16” (W) x 7 31/32” (H) x 11 5/8” (D) Net Weight 25 lbs. (approx.) Shipping Weight 27 lbs. (approx.) Control Complement Touch Control System

Clock: 1:00 - 12:59

Microwave Power for Variable Cooking

Power Level

HIGH ---------------------------------------------------------Full power throughout the cooking time

9 (Sauté) ------- approx. 90% of Full power, 8 (Reheat) ----------- approx. 80%

7 (Med.-High) ------------------- approx. 70%, 6 (Medium) ---------- approx. 60%

5 (Med.-Low) -------------------- approx. 50%, 4 (Defrost) ----------- approx. 40%

3 (Low) ---------------------------- approx. 30%, 2 (Simmer) ---------- approx. 20%

1 (Warm) ------------------------ approx. 10% Nameplate Location Front Accessories Owner’s manual & cooking guide

Glass Turntable

Rotating Ring This microwave oven is designed for household use only. It is not recommended for commercial purposes.

21 7/8” (W) x 17 1/4” (H) x 12 5/8” (D)

14 13/16” (W)

x 15 15/16” (H)

x 9 7/8” (D)

23 7/8” (W)

x 19 13/16” (H)

x 13 9/16” (D) 17 17/32” (W)

x 18 21/32” (H)

x 10 7/8” (D)

Specification Information

Item Description

Model ACM0720A* ACM1120A*

Power Requirement 120 Volts AC 60 Hz

1,050 Watts (9.3A)

Single phase, 3 wire grounded Power Output 700 Watts full microwave power (IEC705) 1100 Watts full microwave power (IEC705) Microwave Frequency 2,450 MHz Timer 0 ~ 99 min. 99 sec. Outside Dimensions 19” (W) x 11” (H) x 12 7/8” (D) 20 7/8” (W) x 12 3/8” (H) x 15 1/2” (D) Cavity Dimensions 12 1/4” (W) x 7 3/4” (H) x 12 1/2” (D) 13 3/4” (W) x 8 3/4” (H) x 14 5/8” (D) Net Weight 25 lbs. (approx.) 35 lbs. (approx.) Shipping Weight 27 lbs. (approx.) 39 lbs. (approx.) Control Complement Touch Control System

Nameplate Location Front

120 Volts AC 60 Hz

1,500 Watts (13A)

Single phase, 3 wire grounded

Accessories Owner’s manual & cooking guide

Glass Turntable

Rotating Ring This microwave oven is designed for household use only. It is not recommended for commercial purposes.

Item Description

Model ACM0860A* MMC5086AA*

Power Requirement 120 Volts AC 60 Hz

1,200 Watts (10.5 A)

Single phase, 3 wire grounded Power Output 800 Watts full microwave power (IEC705) Microwave Frequency 2,450 MHz Timer 0 ~ 99 min. 99 sec. Outside Dimensions 19” (W) x 11” (H) x 12 7/8” (D) Cavity Dimensions 12 1/4” (W) x 7 3/4” (H) x 12 1/2” (D) Net Weight 25 lbs. (approx.) Shipping Weight 27 lbs. (approx.) Control Complement Touch Control System

Nameplate Location Front

Accessories Owner’s manual & cooking guide

Glass Turntable

Rotating Ring This microwave oven is designed for household use only. It is not recommended for commercial purposes.

General Information

Placement of the Oven

This microwave can be easily placed in the kitchen, family room, or anywhere else in the house. Place the oven on a flat surface such as a kitchen countertop or a specially designed microwave oven cart. Do not place oven above a gas or electric range. Free air flow around the oven is important.

Do Not Block Air Vents

All air vents must be kept clear during cooking. If air vents are covered during operation the oven may overheat. In this case, a sensitive thermal safety device automatically turns the oven off. The oven will be inoperable until the oven has cooled sufficiently.

Location of Model Number

To request service information or replacement parts, the service center will require the complete model, serial, and manufacturing number of your microwave oven. The number is located on the oven front as shown in the illustration below.

Cavity Front

Service

Keep a copy of sales receipt for future reference or in case warranty service is required. To locate an authorized servicer:

• For Amana product call 1-800-628-5782 or visit the Web Site at www.amana.com

• For Maytag/Jenn-Air product call 1-800-462-9824 or visit the Web Site at www.maytag.com or www.jennair.com

• For product in Canada call 1-866-587-2002 or visit the Web Sites at www.amana.com or www.maytag.com or www.jennair.com

Warranty service must be performed by an authorized servicer. We also recommend contacting an authorized servicer, if service is required after warranty expires.

Parts and Accessories

Purchase replacement parts and accessories over the phone. To order accessories for your product call:

• For Amana product call 1-877-232-6771 or visit the Web Site at www.amana.com

• For Maytag/Jenn-Air product call 1-800-462-9824 or visit the Web Site at www.maytag.com or www.jennair.com

• For product in Canada call 1-866-587-2002 or visit the Web Sites at www.amana.com or www.maytag.com or www.jennair.com

Model Identification

Complete enclosed registration card and promptly return. If registration card is missing:

• For Amana product call 1-800-843-0304 or visit the Web Site at www.amana.com

• For Maytag product call 1-800-688-9900 or visit the Web Site at www.maytag.com

• For Jenn-Air product call 1-800-536-6247 or visit the Web Site at www.jennair.com

• For product in Canada call 1-866-587-2002 or visit the Web Sites at www.amana.com or www.maytag.com or www.jennair.com

When contacting provide product information located on rating plate. Record the following:

Model Number: ___________________ Manufacturing Number: ___________________ Serial or S/N Number: ___________________ Date of purchase: ___________________ Dealer’s name and address: ___________________

Extended Service Plan

We offer long-term service protection for this new oven.

• Asure™ Extended Service Plan is specially designed to supplement Amana’s strong warranty. This plan covers parts, labor, and travel charges. Call 1-866-232-6244 for information.

• Dependability PlusSM Extended Service Plan is specially designed to supplement Maytag’s and Jenn-Air’s strong warranty. This plan covers parts, labor, and travel charges. Call 1-800-925-2020 for information.

Radio Interference

1. Microwave oven operation may interfere with the radio

or TV reception.

2. When there is interference, it may be reduced or

eliminated by taking the following measures:

• Clean the door and the seal surface of the oven.

• Re-orient the receiving antenna of the radio or TV.

• Relocate the microwave oven in relation to the radio or TV.

• Move the microwave away from the receiver.

• Plug the microwave into a different outlet so that the microwave and receiver are on different branch circuits.

General Information

Electrical Requirements

The oven is designed to operate on a Standard 120 VAC, 60 Hz household outlet. Be sure the circuit is at least 15 or 20 A and the microwave oven is the only appliance on the circuit. It is not designed for 50 Hz or any circuit other than a 120 VAC, 60 Hz circuit.

· Electrical Rating of the Oven: 120 VAC, 60 Hz

Cleaning

Before cleaning the oven, unplug the power supply cord. If impossible, open the oven door to prevent an accidental oven start.

Inside of the Oven

Use a damp cloth to wipe out crumbs and spillovers. It is important to keep the area between door and cavity front clean to assure a tight seal. Remove greasy spatters with a sudsy cloth, then rinse and dry. Do not use harsh detergent or abrasive cleaners.

Glass Tray

The glass tray can be washed by hand or in the dishwasher.

Grounding Instructions

This appliance must be grounded. If an electrical short circuit occurs, grounding reduces the risk of electric shock by providing an escape wire for the electric current. The cord for this appliance has a grounding wire with a grounding plug. Put the plug into an outlet that is properly installed and grounded.

WARNING

To avoid risk of electric shock, personal injury or death, use grounding plug properly.

Ask a qualified electrician if you do not understand the grounding instructions or if you wonder whether the appliance is properly grounded.

Keep the electrical power cord dry and do not pinch or crush it in any way.

Properly Polarized and

Grounded Outlet

Control Panel

Wipe with a damp cloth followed immediately by a dry cloth. The Child Lock feature is also useful when cleaning the control panel. Child Lock prevents accidental programming when wiping the control panel (if so equipped).

Door

If steam accumulates inside or around the outside of the oven door, wipe the panel with a soft cloth. This may occur when the microwave oven is operated under high humidity conditions and in no way indicates a malfunction of the unit.

Outside Oven Surface

Clean with damp cloth. To prevent damage to the operating parts inside the oven, the water should not be allowed to seep into the ventilation openings.

After cleaning the oven, be sure that the rotating ring and the glass tray are in the right position. Press the STOP/ CLEAR pad twice to reset any accidental key setting.

Three-Pronged (Grounding) Plug

For a permanently connected appliance: This appliance must be connected to a grounded, metallic, permanent wiring system, or an equipment grounding conductor should be run with the circuit conductors and connected to the equipment grounding terminal or lead on the appliance.

General Information

Microwave Oven Description

Oven Front Plate

Window Door Screen

Door Seal

Display Window

Control Panel

Door Open Button

Safety Door Lock System Turntable

Rotating Ring

Testing Procedures

WARNING

NOTES:

• Perform microwave energy leakage test if unit is serviced for any reason.

• Verify wire leads are connected to correct positions.

• When removing wire terminal plugs from connectors, grasp the connector, not the wires.

Primary Interlock Switch Test

When the door is opened slowly, an audible click should be heard. If the latch does not activate the switch when the door is closed, the switch should be adjusted in accordance with the adjustment procedure.

1. Disconnect power to oven and remove outer case,

(see “Outer Case” section in Disassembly Procedure).

2. Remove control panel, (see “Control Panel” section

in Disassembly Procedure).

3. Discharge high voltage capacitor, (see "High Voltage

Capacitor" section in Disassembly Procedure).

4. Disconnect wire leads from switch.

5. Perform a continuity test by connecting one meter

lead on COM terminal and the other meter lead on NO terminal.

Readings should be as follows:

Door closed .................0 ohms

Door opened ...............Infinite ohms

NOTE: When replacing component use identical

replacement part.

Disconnect power before performing the following procedures unless testing requires power.

NOTE: When replacing component use identical

replacement part.

NOTE: After repairing the door or the interlock system,

it is necessary to do a continuity test before operating the oven.

Interlock Monitor Switch Test

1. Disconnect power to oven and remove outer case, (see “Outer Case” section in Disassembly Procedure).

2. Remove control panel, (see “Control Panel” section in Disassembly Procedure).

3. Discharge high voltage capacitor, (see "High Voltage Capacitor" section in Disassembly Procedure).

4. Disconnect wire leads from switch.

5. Perform a continuity test by connecting one meter lead on COM terminal and the other meter lead on NC terminal.

Readings should be as follows:

Door closed .................Infinite ohms

Door opened ...............0 ohms

NOTE: When replacing component use identical

replacement part.

NOTE: After repairing the door or the interlock system,

it is necessary to do a continuity test before operating the oven.

Secondary Interlock Switch Test

1. Disconnect power to oven and remove outer case, (see “Outer Case” section in Disassembly Procedure).

2. Remove control panel, (see “Control Panel” section in Disassembly Procedure).

3. Discharge high voltage capacitor, (see "High Voltage Capacitor" section in Disassembly Procedure).

4. Disconnect wire leads from switch.

5. Perform a continuity test by connecting one meter lead on COM terminal and the other meter lead on NO terminal.

Readings should be as follows:

Door closed .................0 ohms

Door opened ...............Infinite ohms

NOTE: After repairing the door or the interlock system,

it is necessary to do a continuity test before operating the oven.

Magnetron

1. Disconnect power to oven and remove outer case, (see “Outer Case” section in Disassembly Procedure).

2. Discharge high voltage capacitor, (see "High Voltage Capacitor" section in Disassembly Procedure).

3. Disconnect wire leads to magnetron.

4. Measure the resistance across filament terminals of the magnetron.

Reading should be less than 1 ohm.

5. Measure the resistance from each filament terminal to ground. Reading should indicate infinite ohms.

NOTE: Any other readings then what should be

indicated, magnetron needs to be replaced.

NOTE: Replace the magnetron if magnetron indications

are OK and all other high voltage components test good (but the unit does not sufficiently heat).

Testing Procedures

WARNING

High Voltage Diode

1. Disconnect power to oven and remove outer case, (see “Outer Case” section in Disassembly Procedure).

2. Discharge high voltage capacitor, (see "High Voltage Capacitor" section in Disassembly Procedure).

3. Disconnect wire leads to high voltage diode.

4. Measure resistance of diode with meter leads. Reverse meter leads and measure again. Normal reading would be continuity in one direction and infinity in the other. An abnormal reading would be continuity or infinity in both directions.

High Voltage Transformer

1. Disconnect power to oven and remove outer case, (see “Outer Case” section in Disassembly Procedure).

2. Discharge high voltage capacitor, (see "High Voltage Capacitor" section in Disassembly Procedure).

3. Disconnect wire leads to high voltage transformer.

4. Measure resistance of the terminals on the high voltage transformer with meter on R x 1 scale.

ACM1120, ACM1420, ACM1460, ACM2160 reading should be indicated as follows:

Primary winding......approximately 0.2 to 0.4 ohm

Filament winding ....less than 1 ohm

Secondary winding.. approximately 60 to 90 ohm

ACM0720, ACM0860, MMC5086, UMC1061,

UMC5200 reading should be:

Primary winding ......approximately 0.3 to 0.8 ohm

Filament winding ....less than 1 ohm

Secondary winding .approximately 100 to 200 ohm

5. Measure resistance of the terminals on the high voltage transformer with meter on high scale.

ACM0720, ACM0860, ACM1120, ACM1420, ACM1460, ACM2160, MMC5086, UMC1061 reading should be indicated as follows:

Primary winding to ground....... Infinite ohms

Filament winding to ground ..... Infinite ohms

Fan Motor

1. Disconnect power to oven and remove outer case, (see “Outer Case” section in Disassembly Procedure).

2. Discharge high voltage capacitor, (see "High Voltage Capacitor" section in Disassembly Procedure).

3. Disconnect wire terminals from fan motor.

4. Measure resistance of fan motor from terminal to terminal.

ACM0720, UMC1061, UMC5200 reading should be indicated as follows:

Terminal A to terminal B ........ 65 – 80 ohms

Terminal B to terminal C ........ 10 – 30 ohms

Terminal A to terminal C ........ 85 – 105 ohms

• Abnormal reading—Infinite or several ohms

Disconnect power before performing the following procedures unless testing requires power.

ACM0860, ACM1120, ACM1420, ACM1460,

ACM2160, MMC5086 reading should be indicated as follows:

Terminal A to terminal C ........ 85 – 100 ohms

Terminal B to terminal C ....... 10 – 25 ohms

• Abnormal reading—Infinite or several ohms

Turntable Motor

1. Disconnect power to oven and remove turntable glass.

2. Turn unit on its side and remove turntable motor cover.

3. Disconnect wire terminals from turntable motor.

4. Measure resistance of turntable motor from terminal to terminal.

• Normal reading—Approximately 100 – 150 ohms

• Abnormal reading—Infinite or several ohms

High Voltage Capacitor

1. Disconnect power to oven and remove outer case, (see “Outer Case” section in Disassembly Procedure).

2. Discharge high voltage capacitor, (see "High Voltage Capacitor" section in Disassembly Procedure).

3. Disconnect wire leads to high voltage capacitor.

4. Measure resistance of capacitor from terminal to terminal.

• Normal reading—momentarily indicates several

ohms and then gradually returns to infinite ohms.

• Abnormal reading—Indicates continuity or infinite

ohms.

5. Measure resistance of capacitor from terminal to case.

• Normal reading—Indicates infinite ohms

• Abnormal reading—Indicates continuity

Humidity Sensor

1. Disconnect power to oven and remove outer case, (see “Outer Case” section in Disassembly Procedure).

2. Discharge high voltage capacitor, (see "High Voltage Capacitor" section in Disassembly Procedure).

3. Disconnect wire terminal plug from control board.

4. Measure the following terminals with meter on R x 1000 scale.

Normal reading:

Old Models New Models

Terminal 1 to 2 ............ 718 ohms ...... 5.1 K ohms

Terminal 2 to 3 ............ 718 ohms ...... 2.1 K ohms

Terminal 1 to 3 ............ 5 ohms.......... 2.1 K ohms

Abnormal reading—Infinite or several ohms

NOTE: Unit should be plugged in for at least 5 minutes

before operating sensor cooking. Room temperature should not exceed 95°F. Oven does not generate microwave energy for the first 28 seconds of operation.

Testing Procedures

WARNING

Relay

1. Disconnect power to oven and remove control panel, (see “Control Panel” section in Disassembly Procedure).

2. Discharge high voltage capacitor, (see "High Voltage Capacitor" section in Disassembly Procedure).

3. Disconnect wire terminal plug from control board relay (RY2), and connect meter leads to terminals shown below on R x 1 scale and operate the unit.

y 2

Rela

Power Level Cycles On for: Cycles Off for:

1 4 seconds 18 seconds 2 6 seconds 16 seconds 3 8 seconds 14 seconds 4 10 seconds 12 seconds 5 12 seconds 10 seconds 6 14 seconds 8 seconds 7 16 seconds 6 seconds 8 18 seconds 4 seconds 9 20 seconds 2 seconds 10 22 seconds 0 seconds

Disconnect power before performing the following procedures unless testing requires power.

Oven Thermostat

1. Disconnect power to oven and remove outer case, (see “Outer Case” section in Disassembly Procedure).

2. Discharge high voltage capacitor, (see "High Voltage Capacitor" section).

3. Remove outer case, (see "Outer Case" section).

4. Remove screws securing air duct to oven cavity.

5. Disconnect wires from oven thermostat.

6. Measure resistance from terminal to terminal. Meter should read approximately 0.5 ohms. Any other indication replace oven thermostat.

Listed below are temperature settings for the thermostat.

Unit Open Closed

ACM0720 ACM0860

ACM1120 ACM1420 ACM1460 ACM2160 MMC5086 UMC1061 UMC5200

230°F 140°F

194°F 167°F

Fuse

NOTE:

Before replacing a blown monitor fuse, test the primary interlock switch, secondary interlock switch, monitor switch, and power relay contacts for proper operation. If the monitor fuse is blown by a failed switch operation, all switches and printed circuit board must be replaced.

Problem:

• Fuse blows immediately after oven door is opened or

closed.

Improper operation of primary, secondary and/or monitor switches

• Fuse blows when oven door is closed and START pad

is pressed.

Malfunction of the high voltage transformer, high voltage capacitor including the diode, magnetron, blower motor or circuit board.

Testing Procedures

WARNING

Control Key Panel

1. Disconnect power to oven and remove outer case, (see “Outer Case” section in Disassembly Procedure).

2. Remove control panel, (see “Control Panel” section in Disassembly Procedure).

3. Discharge high voltage capacitor, (see "High Voltage Capacitor" section in Disassembly Procedure).

4. Disconnect ribbon connector by sliding top part of connector upward. Once in released position remove ribbon from connector by sliding ribbon side-to-side.

NOTE: Caution should be used when removing cable

from connector. Ribbon cable has two holes which connector locks the ribbon in place.

Key pad matrix for ACM0720A*, UMC1061A*, UMC5200A* Pad Conn. Pad Conn.

1 ...................... 1 - 8 Stop/Clear ................. 4 - 8

2 ...................... 1 - 9 Auto Defrost.............. 4 - 9

3 ...................... 1 - 10 Clock ........................ 4 - 10

4 ...................... 1 - 11 Popcorn .................... 5 - 8

5 ...................... 2 - 8 Potato ....................... 5 - 9

6 ...................... 2 - 9 Beverage .................. 5 - 10

7 ...................... 2 - 10 Dinner Plate .............. 5 - 11

8 ...................... 2 - 11 Fresh Vegetable........ 6 - 8

9 ...................... 3 - 8 Frozen Entree ........... 6 - 9

0 ...................... 3 - 9 Start .......................... 6 - 10

Program .......... 3 - 10 Timer ........................ 7 - 9

Power Level..... 3 - 11 Easy Cook ................ 7 - 10

Disconnect power before performing the following procedures unless testing requires power.

Key pad matrix for ACM0860A*, ACM1460A*, ACM2160A*, and MMC5086A* Pad Conn. Pad Conn.

Sensor Popcorn.. 1 - 8 Start ....................... 4 - 10

Easy Cook .......... 1 - 9 4 ............................ 4 - 11

Power level ......... 1 - 10 Control Set-up ....... 5 - 8

1 ......................... 1 - 11 8 ............................ 5 - 10

Warm Hold .......... 2 - 8 5 ............................ 5 - 11

Program .............. 2 - 10 Timer ...................... 6 - 8

2 ......................... 2 - 11 More ...................... 6 - 9

Rapid Defrost ..... 2 - 12 9 ............................ 6 - 10

Sensor Cook....... 3 - 8 6 ............................ 6 - 11

Sensor Reheat ... 3 - 9 Clock ..................... 7 - 8

Stop /Clear ......... 3 - 10 Less ....................... 7 - 9

3 ......................... 3 - 11 0 ............................ 7 - 10

Auto Defrost ....... 4 - 8 7 ............................ 7 - 11

Auto Cook........... 4 - 9

Key pad matrix for ACM1120A* and ACM1420A* Pad Conn. Pad Conn.

Clock .................. 1 - 8 Beverage ............... 5 - 8

Control Set-up .... 1 - 9 Potato .................... 5 - 9

More ................... 1 - 10 Popcorn ................. 5 - 10

Less.................... 1 - 11 Pizza...................... 5 - 11

6 ......................... 2 - 8 Timer ..................... 5 - 12

7 ......................... 2 - 9 Auto Defrost .......... 6 - 8

8 ......................... 2 - 10 Program ................ 6 - 9

9 ......................... 2 - 11 Power Level ........... 6 - 10

0 ......................... 2 - 12 Rapid Defrost ........ 6 - 12

Stop/Clear .......... 3 - 8 1 ............................ 7 - 8

Fresh Vegetable . 3 - 9 2 ............................ 7 - 9

Easy Cook .......... 3 - 12 3 ............................ 7 - 10

Frozen Entree ..... 4 - 10 4 ............................ 7 - 11

Start .................... 4 - 11 5 ............................ 7 - 12

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