Panasonic NN-S543WF, Service Manual

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DANGER OF HIGH VOLTAGE AND HIGH TEMPERATURE (HOT/LIVE) OF THE INVERTER POWER SUPPLY
(U)
INVERTER WARNING
This Inverter board looks like a regular PCB. However, this PCB drives the magnetron tube with extremely high voltage
and high current.
IT HAS: 1. Very high voltage and high current circuits.
It functions the same as the high voltage transformer and high voltage capacitor in ordinary microwave ovens.
2. Aluminum heat sink is energized with very high voltages and high heat energy.
3. Very high voltage may remain in circuitry even when oven is off. High voltage may remain in the capacitors
on the board.
DO NOT:
1. Do not touch circuitry because it has very hot (high voltage) circuitry. Even when replacing board, extreme
care should be taken to avoid possible electric shock hazards. High voltage may remain in circuit.
2. Do not touch aluminum heat sink because it is very hot in high voltage and also very hot in high heat energy.
3. Do not try to adjust or tamper with preset volume on the Inverter board because it is very dangerous to
adjust without proper test equipment.
4. Do not test oven while Inverter grounding plate or screws are loose. It is very dangerous to operate H.V.
Inverter Circuit (U) with loose mounting screws or if improperly grounded.
5. For USA only:
Do not try to repair Inverter PCB because it is very dangerous to repair it. Replace as whole High Voltage
Inverter Circuit unit and return fully re-packed with original shipping box and shipping materials.
INVERTER POWER SUPPLY DIAGRAM
NEW HV
- 2 -
*
*
*
*
*
HEAT SINK
(RECTIFIER BRIDGE)
CHOKE COIL
CURRENT
TRANSFORMER
SAND BAR
RESISTOR
HIGH VOLTAGE
TRANSFORMER
PCB
FILM CAPACITORS
VARISTOR
PRIMARY WINDINGS
SECONDARY
WINDINGS
HIGH VOLTAGE
DIODES
DO NOT TOUCH
LEAD
WIRE
GROUNDING
PLATE
*
4
INVERTER
SUPPORT
BRACKET OF ORIFICE
H.V INVERTER(U) * 3