Inverter Warnings - Panasonic NN-A574SBBPQ Service Manual

4 Inverter Warnings

The inverter circuit board supplies the magnetron tube with a very high voltage (4000 volts).
RECTIFIER BRIDGE
CHOKE COIL
SAND BAR RESISTOR
CURRENT TRANSFORMER
PRESET VOLUME *4
(DO NOT ADJUST)
CONTROL BOARD
WITH CUSTOM IC
PHOTOCOUPLER
• The inverter circuit board operates at high voltages
and high temperatures.
The Inverter PCB
• Operates at a very high voltage and current.
• Has an aluminium heat sink which becomes very
hot.
• Has capacitors in the circuitry that hold a high volt-
age charge even when the oven is not operating.
Warning
• Do not touch the high voltage circuit. When replac-
ing the board care must be taken to avoid possible
electric shock.
• Do not touch the aluminium heat sink as it is part of
the high voltage circuit and becomes very hot.
• Do not attempt to repair the inverter PCB, this
can be very dangerous. Replace the high volt-
age inverter circuit as a complete unit.
• Do not adjust or tamper with the pre-set volume on
the inverter board. It is very dangerous to adjust
this pre-set without proper test equipment.
• Do not operate the microwave oven when the
inverter grounding plate and fixing screw is loose.
It is very dangerous to operate the inverter circuit
board without a proper ground connection.
HEAT SINK
CN 701
HIGH VOLTAGE TRANSFORMER
Danger
HIGH VOLTAGE AREA *1
DO NOT TOUCH
HOT/HIGH VOLTAGE *2
figure 1Assembly of the inverter circuit board
5
FILM CAPACITORS
HIGH VOLTAGE
DIODES
HIGH VOLTAGE
CAPACITORS
CN 703
H.V.INVERTER(U)
GROUNDING BRACKET
INVERTER SUPPORT BRACKET