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Discharging the high voltage capacitors

WARNING

There is high voltage present with high current capabilities
in the circuits of the primary and secondary windings, choke
coil and heat sinkof the inverter. It is extremely dangerous
to work on or near these circuits with the oven energized.
DO NOT measure the voltage in the high voltage circuit
including the filament voltage of the magnetron.

WARNING

Never touch any circuit wiring with your hand or with an
insulated tool during operation.

3.3. Part replacement.

When troubleshooting any part or component is to be replaced,
always ensure that the power cord is unplugged from the wall
outlet.

3.4. When the 16A fuse is blown

due to the malfunction of the
short switch:

WARNING

When the 16A 250V fuse is blown due to the malfunction of
the short switch, replace all of the components (primary
latch switch, short switch and power relay RY1).
 1. This is mandatory. Refer to “measurements and

adjustments” for the location of these switches.

 2. When replacing the fuse, confirm that it has the

appropriate rating for these models.

 3. When replacing faulty switches, be sure the mounting

tabs are not bent, broken or deficient in their ability to
hold the switches.

3.5. Avoid inserting nails, wire etc.

through any holes in the unit
during operation.

Never insert a wire, nail or any other metal object through the
lamp holes on the cavity or any holes or gaps, because such
objects may work as an antenna and cause microwave
leakage.

3.6. Verification after repair

 1. After repair or replacement of parts, make sure that the

screws of the oven, etc. are neither loosen or missing.
Microwave energy might leak if screws are not properly
tightened.

 2. Make sure that all electrical connections are tight before

inserting the plug into the wall outlet.

 3. Check for microwave energy leakage.

CAUTION OF MICROWAVE RADIATION LEAKAGE

USE CAUTION NOT TO BECOME EXPOSED TO
RADIATION FROM THE MICROWAVE MAGNETRON OR
OTHER PARTS CONDUCTING MICROWAVE ENERGY.

IMPORTANT NOTICE

 1. The following components have potentials above 2000V

while the appliance is operated.

 • 

Magnetron

 • 

High voltage transformer (Located on inverter (U))

 • 

High voltage diodes (Located on inverter (U))

 • 

High voltage capacitors (Located on inverter (U))

Pay special attention to these areas.

 2. When the appliance is operated with the door hinges or

magnetron installed incorrectly, the microwave leakage
can exceed more than 5mW/cm

2

. After repair or

exchange, it is very important to check if the magnetron
and the door hinges are correctly installed.

3.7. Sharp edges

CAUTION

Please use caution when disassembling or reassembling
internal parts. Some exposed edges may be sharp to the
touch and can cause injury if not handled with care.

8

NN-A574SF / NN-A554WF / NN-A524MF / NN-CT579S / NN-CT569M / NN-CT559W

Summary of Contents for NN-A524MF

Page 1: ...onic Home Appliances Microwave Oven Shanghai Co Ltd 2009 NN A574SF NN A554WF NN A524MF NN CT579S NN CT569M NN CT559W BXQ U K BPQ U K EPG Continental Europe GPG Germany Microwave Oven ORDER NO PHAMOS0906043C2 ...

Page 2: ...2 NN A574SF NN A554WF NN A524MF NN CT579S NN CT569M NN CT559W ...

Page 3: ...3 NN A574SF NN A554WF NN A524MF NN CT579S NN CT569M NN CT559W ...

Page 4: ...imary Secondary Latch Switch interlocks Power Relay RY1 16 5 2 Short Switch 16 5 3 Magnetron 16 5 4 key board membrane Membrane switch assembly 16 5 5 Inverter power supply U 17 5 6 Temperature thermistor 17 6 MEASUREMENTS AND ADJUSTMENTS 18 6 1 Adjustment of primary latch switch secondary latch switch and short switch 18 6 2 Measurement of microwave output 18 7 TROUBLESHOOTING GUIDE 19 7 1 Troubl...

Page 5: ...1 SCHEMATIC DIAGRAM 5 NN A574SF NN A554WF NN A524MF NN CT579S NN CT569M NN CT559W ...

Page 6: ...e digital programer circuit determines the power level and cooking time to complete cooking and indicates the operating state in the display window 2 When cooking time in the display window has elapsed the oven turns off automatically by a control signal from the digital programmer circuit 2 4 Thermistor The thermistor which fixed on magnetron detects magnetron temperature and make power down when...

Page 7: ...ay be HOT due to heat energy therefore extreme care should be taken during servicing H V Inverter warning WARNING FOR INVERTER POWER SUPPLY U GROUNDING Check the High Voltage Inverter Power Supply circuit grounding The high voltage inverter power supply circuit board must have a proper chassis ground The inverter grounding plate must be connected to the chassis If the inverter board is not grounde...

Page 8: ...Never insert a wire nail or any other metal object through the lamp holes on the cavity or any holes or gaps because such objects may work as an antenna and cause microwave leakage 3 6 Verification after repair 1 After repair or replacement of parts make sure that the screws of the oven etc are neither loosen or missing Microwave energy might leak if screws are not properly tightened 2 Make sure t...

Page 9: ...Unplug lead wires from Inverter Power Supply U primary terminals 2 Connect test probes of ohm meter to the disconnected leads that were connected to Inverter Power Supply U 3 Test the continuity of short switch with door opened and closed positions using lowest scale of the ohm meter Normal continuity readings should be as follows Door Opened Door Closed 0Ω Close Ω Open 5 3 Magnetron Continuity ch...

Page 10: ... supply cord into outlet 4 Program DPC a Press Clock pad once b Press Delay Stand pad once c Press Start pad once d Press Micro Power pad once 5 Program oven at High power for 1 minute and press Start pad a After approximately 3 seconds oven stops operating b During oven operation the input current is approximately 0 4A INPUT CURRENT FAILURE CODE Unplug CN701 0 4A Oven stops in 3 seconds after sta...

Page 11: ...component test procedures 6 2 Measurement of microwave output The output power of the magnetron can be determined by performing IEC standard test procedures However due to the complexity of IEC test procedures it is recommended to test the magnetron using the simple method outlined below Necessary Equipment 1 liter beaker Glass thermometer Wrist watch or stopwatch NOTE Check the line voltage under...

Page 12: ...ys touch ground while working on this panel to discharge any static charge in your body 7 230 240V AC is present on the digital programmer circuit Terminals of power relay s and primary circuit of Digital Programmer Circuit When troubleshooting be cautious of possible electrical shock hazard Before troubleshooting operate the microwave oven following the correct operating procedures in the instruc...

Page 13: ...ction of high voltage circuit especially magnetron filament circuit NOTE Large contact resistance will cause lower magnetron filament voltage and cause magnetron to have lower output and or be intermittent 3 Defective high voltage component H V Inverter Power Supply U Magnetron Check high voltage component according to component test procedure and replace if it is defective 4 Open or loose wiring ...

Page 14: ...am the DPC into TEST MODE press Clock pad once press Delay Stand pad once Press Start pad once press Micro Power pad once Program unit for operation H95 H97 H98 H99 appears in display window a short time after Start pad is pressed and there is no microwave oscillation Alternate way to troubleshoot oven with AC Ampere meter used H95 H97 H98 H99 appears in display window a short time after Start pad...

Page 15: ...l Ammeter reading is To do Remedy Shut off in 23 seconds after Start 1 Between 0 5A and 1 0A Check and repair open magnetron circuit Open magnetron wiring between Inverter and magnetron terminal 2 Between 1 0A and 2 0A Check continuity of D702 in Inverter PCB 1 D702 shorted Replace H V Inverter Z606YM300BP 2 D702 is OK Replace magnetron Shut off in 3 seconds after Start 1 Less than 0 5A Check open...

Page 16: ...ACITOR 1 C703 ZCWF2395N632 FILM CAPACITOR 1 DB701 Z0FBBS000001 RECTIFIER BRIDGE 1 L701 Z5020M300XN CHOKE COIL 1 R702 Z0CM352JA002 SAND BAR RESISTOR 1 T701 Z609A7F40QP TRANSFORMER 1 INCLUDING D701 D702 C706 C707 D701 D702 Z0FBAZ000002 DIODE 2 C706 Z0C3F562A002 FILM CAPACITOR 1 5600PF 3KV C707 Z0C3F432A002 FILM CAPACITOR 1 4300PF 3KV 23 NN A574SF NN A554WF NN A524MF NN CT579S NN CT569M NN CT559W ...

Page 17: ...8 EXPLODED VIEW AND PARTS LIST 8 1 EXPLODED VIEW 24 NN A574SF NN A554WF NN A524MF NN CT579S NN CT569M NN CT559W ...

Page 18: ...NDARY LATCH SWITCH 28 Z61785U30XN MICRO SWITCH 1 SHORT SWITCH 29 Z2M236 M42JP MAGNETRON 1 31 Z65797550GP FUSE 1 BPQ BXQ 10A 31 Z62306V60BP FUSE 1 EPG GPG 10A 32 Z6331 1T50 FUSE 1 16A 33 Z607X9G00BP NOISE FILTER U 1 34 Z63265U30XN TURNTABLE MOTOR 1 35 Z900C8W00BP AC CORD W PLUG 1 BPQ BXQ 35 Z900C8W00EP AC CORD W PLUG 1 EPG GPG 36 Z606YM300BP H V INVERTER U 1 37 Z65857X50BP INVERTER BRACKET 1 38 Z66...

Page 19: ...AN MOTOR 1 67 Z40087X50BP PULLEY B 1 68 Z402L7X50BP FAN CASE UNIT 1 70 Z22397X50BP CONVECTION FAN 1 71 Z41327X50BP PULLEY A 1 72 Z22787X50BP FAN CASE COVER 1 73 Z41457X50BP LEFT AIR GUIDE 1 74 Z41807X50BP MOTOR BRACKET 1 75 Z10587X50BP BACK COVER 1 26 NN A574SF NN A554WF NN A524MF NN CT579S NN CT569M NN CT559W ...

Page 20: ...S EPG D3 Z301P5R00AP DOOR E U 1 D4 Z30215G10XN DOOR KEY SPRING 1 D5 Z30855Q00AP DOOR C 1 D7 Z31467X60BP DOOR SCREEN B 1 A524MF BXQ A554WF BXQ CT569M BPQ CT559W BPQ D7 Z31467X60GP DOOR SCREEN B 1 CT569M GPG CT559W GPG D8 Z30017X60SBP DOOR A 1 A524MF BXQ CT569M BPQ GPG D8 Z30017X60HBP DOOR A 1 A554WF BXQ CT559W BPQ GPG 27 NN A574SF NN A554WF NN A524MF NN CT579S NN CT569M NN CT559W ...

Page 21: ...SBP BUTTON 1 A574SF BXQ CT579S BPQ GPG E6 Z80727X50SBP DOOR OPENING BUTTON 1 A574SF BXQ CT579S BPQ GPG E7 Z80375K00AP COOK BUTTON SPRING 1 E8 Z82567X50BP DOOR OPENING LEVER 1 A574SF BXQ CT579S BPQ GPG E11 Z60707X50BP INSULATION SHEET 1 A574SF BXQ CT579S BPQ GPG E12 Z66017X50BP GROUNDING PANEL 1 A574SF BXQ CT579S BPQ GPG E13 Z80877X50BP SPRING 1 A574SF BXQ CT579S BPQ GPG E14 Z82577X50BP LEVER BACKS...

Page 22: ...H U 1 CT559W GPG E25 Z80345Q00SBP ESCUTCHEON BASE 1 A524MF BXQ CT569M BPQ GPG E25 Z80345Q00HBP ESCUTCHEON BASE 1 A554WF BXQ CT559W BPQ GPG E26 Z80725Q00SAP DOOR OPENING BUTTON 1 A524MF BXQ CT569M BPQ GPG E26 Z80725Q00HAP DOOR OPENING BUTTON 1 A554WF BXQ CT559W BPQ GPG E27 Z80375K00AP COOK BUTTON SPRING 1 E28 Z82565Q00AP DOOR OPENING LEVER 1 A554WF BXQ A524MF BXQ CT559W BPQ GPG CT569M BPQ GPG E35 Z...

Page 23: ...E HARNESS 1 W2 Z030E6W50XP H V LEAD WIRE 1 W3 Z030F7X50GS LEAD WIRE HARNESS U 1 A574SF BXQ CT579S BPQ EPG INCLUDING THERMISTOR W3 Z030F7X60GS LEAD WIRE HARNESS U 1 A554WF BXQ A524MF BXQ CT569 BPQ GPG CT559W BPQ GPG INCLUDING THERMISTOR 30 NN A574SF NN A554WF NN A524MF NN CT579S NN CT569M NN CT559W ...

Page 24: ...027X60SBP PACKING CASE PAPER 1 CT569M BPQ P2 Z01027X60SGP PACKING CASE PAPER 1 CT569M GPG P2 Z01027X60HBP PACKING CASE PAPER 1 CT559W BPQ P2 Z01027X60HGP PACKING CASE PAPER 1 CT559W GPG P3 Z01047X50BP UPPER FILLER 1 P4 Z01057X50BP LOWER FILLER 1 P5 Z01068100XN P E BAG 1 P6 Z01078J00XN DOOR SHEET 1 P7 Z06015Q00AP COOKING TRAY 1 P8 Z01924T00AP SHEET 1 P9 Z01087X60BP RACK PACKING 1 P11 Z10855R00BP PI...

Page 25: ...9 DIGITAL PROGRAMMER CIRCUIT 9 1 SCHEMATIC DIAGRAM NN A574SF CT579S 32 NN A574SF NN A554WF NN A524MF NN CT579S NN CT569M NN CT559W ...

Page 26: ...33 NN A574SF NN A554WF NN A524MF NN CT579S NN CT569M NN CT559W ...

Page 27: ...9 2 SCHEMATIC DIAGRAM NN A554WF A524MF CT569M CT559W 34 NN A574SF NN A554WF NN A524MF NN CT579S NN CT569M NN CT559W ...

Page 28: ...35 NN A574SF NN A554WF NN A524MF NN CT579S NN CT569M NN CT559W 06 09 S 7X6 Printed in China ...

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