GE JES2251SJ Technical Service Guide

11
6 CAUTIONS TO BE OBSERVED WHEN TROUBLESHOOTING
Unlike many other appliances, the microwave oven
is a high voltage, high current device. It is free from
danger in ordinary use, though extreme care should
be taken during repair.
Caution
Servicemen should remove their watches
whenever working close to or replacing the
magnetron.
6.1. Check the grounding
Do not operate on a two wire extension cord. The
microwave oven is designed to be grounded when
used. It is imperative, therefore, to ensure the
appliance is properly grounded before beginning
repair work.
6.2. Inverter warnings
DANGER, HIGH VOLTAGE AND HIGH
TEMPERATURE (HOT/LIVE) OF THE INVERTER
POWER SUPPLY (U)
The High Voltage Inverter Power Supply handles
very high voltage and current for the magnetron
tube. Though it is free from danger in ordinary use,
extreme care should be taken during repair.
The aluminum heat sink is also energized with high
voltage (HOT), do not touch when the AC input
terminals are energized. The power device Collector
is directly connected to the aluminum heat sink.
The aluminum heat sink may 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 bracket must be
connected to the chassis. If the inverter board is
not grounded it will expose the user to very high
voltages and cause extreme DANGER! Be sure
that the inverter circuit is properly grounded via
the inverter grounding bracket.
Grounding of the inverter circuit board
WARNING! DISCHARGE THE HIGH VOLATGE
CAPACITORS
For about 30 seconds after the oven is turned off,
an electric charge remains in the high voltage
capacitors in the Inverter Power Supply circuit
board.
When replacing or checking parts, remove the
power plug from the outlet and short the inverter
output terminal of the magnetron filament terminals
to the chassis ground with an insulated handle
screwdriver to discharge. Please be sure to touch
the chassis ground side first and then short to
the output terminals.
H.V.INVERTER(U)
GROUNDING PLATE
CHECK GROUNDING
DO NOT TOUCH
HEAT SINK
IGBT
CHOKE COIL
RECTIFIER BRIDGE
HIGH VOLTAGE
TRANSFORMER
CN702
DO NOT
ADJUST VR701
SAND BAR
RESISTOR
CN701
SHORT FOR DISCHARGING HIGH
VOLTAGE CHARGE REMAINS IN
HIGH VOLTAGE CAPACITORS
HIGH VOLTAGE
CAPACITORS
HIGH VOLTAGE CHARGE
REMAINS IN HIGH
VOLTAGE CAPACITORS
CN703
HIGH
VOLTAGE
DIODES
SECONDARY
WINDINGS
PRIMARY
WINDINGS
DANGER OF HIGH VOLTAGE
AND HIGH TEMPERATURE
HOT/LIVE OF HEAT SINK
FILM
CAPACITORS

GE JES2251SJ Specifications

General

Brand	GE
Model	JES2251SJ
Category	Microwave Oven
Language	English