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Table of Contents
This service information is designed for experienced repair technicians only and is not designed for use by the
general public. It does not contain warnings or cautions to advise non-technical individuals of potential dangers
in attempting to service a product. Products powered by electricity must be serviced or repaired only by expe-
rienced proffesional technicians. Any attempt to service or repair the product or products dealt with this service
information by anyone else could result in serious injury or death.
There are special components used in this equipment which are important for safety. These parts are marked
by (!) in the schematic diagrams, circuit board diagrams, exploded views and replacement parts lists. It is
essential that these critical parts are replaced with parts specified by the manufacturer, preventing shock, fire
or other hazards. Do not modify the original design without permission from the manufacturer.
! WARNING
IMPORTANT SAFETY NOTICE
Microwave Oven
NN-CT776SBPQ
NN-A734MBEPG
NN-A764WBEPG
NN-A764WBWPG
g
g
HAD0607003C2
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Table of Contents
Related Manuals for Panasonic Inverter NN-CT776SBPQ
Summary of Contents for Panasonic Inverter NN-CT776SBPQ
- Page 1 HAD0607003C2 Microwave Oven NN-CT776SBPQ NN-A734MBEPG NN-A764WBEPG NN-A764WBWPG ! WARNING This service information is designed for experienced repair technicians only and is not designed for use by the general public. It does not contain warnings or cautions to advise non-technical individuals of potential dangers in attempting to service a product.
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Page 2: Table Of Contents
1 Contents Contents ............2 Feature Chart . -
Page 3: Feature Chart
2 Feature Chart Function Microwave Grill Convection Combi Sensor Reheat Sensor Cook Sensor Combi Weight Defrost Weight Combi Weight Reheat Weight Cook Memory Cook Weight Crisp Stage Cooking 3 stage Delay / Stand More / Less Kg -> lb/oz Clock Word Prompt English Step by Step... -
Page 4: Control Panel
3 Control Panel NN-A774/NN-A734/NN-A764* Display Window Time Pads Microwave Power Pad Grill Power Pad Convection Pad Grill Convection Pad Combination Pad Auto Defrost Pad Weight Select Pads (10) Clock Pad AUTO / (11) Delay/Stand Pad (12) Auto Weight Program Pads 10min (13) Panacrunch Program Pads 1min... -
Page 5: Inverter Warnings
4 Inverter Warnings The inverter circuit board supplies the magnetron tube with a very high voltage (4000 volts). HIGH VOLTAGE AREA *1 HEAT SINK DO NOT TOUCH RECTIFIER BRIDGE HOT/HIGH VOLTAGE *2 FILM CAPACITORS CHOKE COIL CN 702 SAND BAR RESISTOR HIGH VOLTAGE CURRENT TRANSFORMER DIODES... -
Page 6: Description Of The Operation Sequence
7 Description of the Operating Sequence 7.1 Variable power cooking control pad pressed: The output power is controlled by the inverter power 1. The digital programmer circuit determines the supply. The level of output from the inverter circuit is power level and the cooking time and indicates the controlled by a pulse width modulated signal from the operating state in the display. -
Page 7: Cautions To Be Observed When Troubleshooting
8 Cautions to be Observed when Troubleshooting The microwave oven is a high voltage, high current This high voltage inverter power supply supplies very device. Although it is free from danger in ordinary use, high voltage and current to the magnetron. Though it extreme care should be taken during repair. - Page 8 work on or near these inverter circuit components. DO NOT measure the voltage in the high voltage circuit including the filament voltage of the magnetron. H.V.INVERTER(U) WARNING Never touch any circuit wiring during operation. GROUNDING PLATE 8.3 Part replacement CHECK GROUNDING When replacing any component in the microwave oven, always ensure that the power cord is removed from the...
- Page 9 When the appliance is operated with the door hinges or magnetron fixed incorrectly, the microwave leakage can reach more than 5mW/cm . After repair or replac- ing parts, it is very important to check if the magnetron and the door hinges are correctly fixed. 8.7 Sharp edges Please use caution when unpacking, installing or mov- ing the unit, as some exposed edges may be sharp to...
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Page 10: Part Replacement Proceedure
9 Parts Replacement Procedure 9.1 Magnetron 4. Remove the 1 screw holding the earth wire to the magnetron. 1. Discharge the high voltage capacitors on the 5. Remove the connector CN701 and CN702 from the inverter circuit. inverter PCB.figure 8 2. - Page 11 9.3 Digital Programmer Circuit (DPC) 1. Carefully remove all solder from the terminal pins of and membrane key board. the low voltage transformer / power relays using a NOTE: Ground any static electric from your body before 30W soldering iron and a solder sucker. handling the digital programmer circuit (DPC).
- Page 12 After replacing component parts of the door, fol- low the instructions below for proper installation and adjustment of the door, this is to prevent microwave leakage. 1. When mounting the door to the oven, adjust the door parallel to the bottom of the oven face plate by adjusting the upper hinge.
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Page 13: Component Test Proceedure
10 Component Test Procedure Caution 3. Check the continuity between each filament termi- nal and the magnetron case, a good magnetron ∞ • The inverter circuit operates at high voltages. indicates infinite resistance. • Never attempt to measure the high voltage on the inverter circuit. - Page 14 DANGER HIGH VOLTAGE AND HIGH TEMPERATURE (HOT/LIVE) HEAT SINK HEAT SINK RECTIFIER BRIDGE FILM CAPACITORS CHOKE COIL CN 702 SAND BAR RESISTOR HIGH VOLTAGE CURRENT TRANSFORMER DIODES PRESET VOLUME *4 (DO NOT ADJUST) HIGH VOLTAGE CAPACITORS CONTROL BOARD WITH CUSTOM IC CN 703 PHOTOCOUPLER HIGH VOLTAGE TRANSFORMER...
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Page 15: Measurements And Adjustments
11 Measurements and Adjustments Warning 4. Stir the water again and read the temperature of the water. (Record as T2). • Only replace parts with parts from the original man- 5. The normal temperature rise at the high power posi- ufacturer. - Page 16 12 Troubleshooting Guide Caution 1. Do not try to repair the H.V. Inverter power supply. Replace the inverter circuit board as a complete unit. 2. Do not adjust the preset volume on the Inverter. It is very dangerous to repair or adjust without special test equiptment, the inverter handles very high voltage and current.
- Page 17 12.1 Troubleshooting (no operation) Symptom Cause Correction 1. Oven is dead. 1. Open or loose lead wire harness. Fuse is OK 2. Open low voltage transformer. No display and no operation at all. 3. Defective DPC AU or DPC DU 2.
- Page 18 12.3 Troubleshooting (other problems) Symptom Cause Correction 1. Microwave output is low. 1. Decrease in power source volt- Consult electrician. Oven takes a long time to cook food. age. Refer to output test procedures. 2. Open or loose wiring of magne- tron filament circuit causing inter- mittent oscillation.
- Page 19 DANGER H97, H98 appears in HIGH the display window. VOLTAGE Open Check magnetron *Check the continuity of the magnetron Magnetron* filament continuity filament. Check the fialment is not shorted to the magnetron case.. DPC board/Power relay Check Inverter input AC Loose relay wiring voltages at CN702 Latch switch...
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Page 20: Digital Programmer Circuit
DANGER H97, H98 appears in HIGH the display window. VOLTAGE DPC board/Power Relay Less than 0.4A Loose wiring. Check oven input Latch Switch. current. DPC control signal More than 0.5A *Check the continuity of the magnetron Open Check magnetron filament. Check the fialment is not shorted to the Magnetron* filament continuity. - Page 21 Microwave oven shuts down Unplug CN702 connec- Abnormal 1. Latch switch between 15 - 33 seconds. tor and measure the 2. DPC/Power relay Set the microwave oven to test voltage between the Normal Step 2 mode (See page ) terminlas Set to high power 1 minute.