LG LMC1575BD Service Manual page 6

DANGER OF HIGH VOLTAGE AND HIGH TEMPERATURE OF THE INVERTER POWER SUPPLY
This inverter board looks like a regular PCB. However, This PCB drive the magnetron with extremely high voltage and high current. Take
cautionary measure when disassembling and troubleshooting the inverter PCB. Improper handling can result in electric shock or burns ,
which might lead to injury or death.
1. Inverter power supply has very high voltage and high current circuit.
It functions the same as the high voltage transformer and high voltage capacitor in ordinary microwave oven.
2. Very high voltage may remain in circuitry even when oven is off. High voltage charge may remain in the capacitors on the board.
After oven off, wait 60 seconds to discharge the high voltage capacitors of inverter unit.
3. 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 charge may remain in circuits
4. Do not touch aluminum heat sink because it is energized very high voltage and it is very hot in high heat energy.
5. Do not test oven while inverter grounding screw is loose. It is very dangerous to operate H.V inverter circuit with loose grounding screw
or if improperly grounded.
Heat sink
Bridge
Diode
Choke coil
Current
Transformer
L - N(Input)
Communication
Connector
Sub PCB
LMC1575BD /00
LMC1575ST /00
LMC1575SW /00
LMC1575SB /00
CAUTIONS
DC capacitor
IGBT
Resonant
capacitor
Earth wire
High Voltage
Diode
MGT(Output)
High Voltage Capacitor
WARNING
Heat sink
Bridge diode
Choke coil
DC capacitor
L - N(Input)
H.V Transformer H.V Transformer
Downloader
Connector
Comm.
Connector
2-2
Shunt resistor
IGBT
Resonant capacitor
Earth wire
High
Voltage
Diode
MGT(Output)
H.V Capacitor
LMC1575BD /01
LMC1575ST /01
LMC1575SW /01
LMC1575SB /01