1 SCHEMATIC DIAGRAM 5
2 DESCRIPTION OF OPERATING SEQUENCE 6
2.1. Variablepower cooking control 6
2.2. Inverterpower supply circuit 6
2.3. Turbodefrost, Auto cook 6
2.4. Sensorcooking 6
2.5. Steamsensor and digital programmer circuit 7
3 CAUTIONS TO BE OBSERVED WHEN TROUBLESHOOTING
8
3.1. Checkthe grounding 8
3.2. Inverterwarnings 8
3.3. Partreplacement. 9
3.4. Whenthe 10A fuse is blown due to the malfunction of the
short switch: 9
3.5. Avoidinserting nails, wire etc. through any holes in the
unit during operation. 9
3.6. Verificationafter repair 9
3.7. Sharpedges 9
4 DISASSEMBLY AND PARTSREPL ACEMENT PROCEDURE
10
4.1. Magnetron 10
4.2. Digitalprogrammer circuit (D.P.C) 10
4.3. Lowvoltage transformer and/or power relays (RY1, RY2)
11
4.4. Fanmotor 11
4.5. Doorassembly 11
4.6. Turntablemotor 13
4.7. Steamsensor 13
4.8. Inverterpower supply 14
5 COMPONENT TEST PROCEDURE 15
5.1. Primary,Secondary Latch Switch interlocks & Power
Relay RY1 15
5.2. ShortSwitch 15
5.3. Magnetron 15
5.4. keyboard membrane (Membrane switch assembly) 15
5.5. Inverterpower supply (U) 16
5.6. Temperaturethermistor 16
6 MEASUREMENTS AND ADJUSTMENTS 17
6.1. Adjustmentof primary latch switch, secondary latch switch
and short switch. 17
6.2. Measurementof microwave output 17
7 TROUBLESHOOTING GUIDE 18
7.1. (Troubleshooting)Oven stops operation during cooking
18
7.2. (Troubleshooting)Other problems 19
7.3. Troubleshootingof inverter circuit (U) and magnetron 20
7.4. Simpleway of H.V. Inverter/magnetron troubleshooting
21
7.5. Howto check the semiconductors using an OHM meter
21
7.6. H.V.INVERTER MAIN PARTS LIST (Z606YBA00QP) 22
8 EXPLODED VIEW AND PARTS LIST 23
8.1. EXPLODEDVIEW 23
8.2. PARTSLIST 24
8.3. ESCUTCHEONBASE ASSEMBLY 25
8.4. DOORASSEMBLY 27
8.5. WIRINGMATERIALS 28
8.6. PACKINGAND ACCESSORIES 29
9 DIGITAL PROGRAMMER CIRCUIT 30
9.1. SCHEMATICDIAGRAM (NN-SD452W) 30
9.2. SCHEMATICDIAGRAM (NN-ST462M, ST452W) 32
CONTENTSPage Page
4
NN-SD452W/ NN-ST462M / NN-ST452W