LG LMHM2237BD Service Manual page 33

COMPONENTS
TOUCH KEY BOARD
NOTES:
• A MICROWAVE ENERGY TEST MUST ALWAYS BE PERFORMED WHEN THE UNIT IS SERVICED FOR
ANY REASON.
• MAKE SURE THE WIRE LEADS ARE IN THE CORRECT POSITION.
• WHEN REMOVING THE WIRE LEADS FROM THE PARTS, BE SURE TO GRASP THE CONNECTOR, NOT
THE WIRES.
TEST
Measure the resistance between terminal
pins of connector KEY CONNECTOR.
NOTE:
When reconnecting the FPC connector,
make sure that the holes on the FPC
connector are properly engaged with hooks
on the plastic fastener.
MATRIX CIRCUIT FOR
TOUCH KEY BOARD
CONNECTOR (KEY CON)
KEY MATRIX
2st 1 2 3
8
9
Clear Vent Hi/Low/Off Clock Energy Saving
10
1 2 3 4
11
7 8 9 0
time & weight
12
Sensor Popcorn N.A N.A
13
Start C/T Lamp On/Off Hold Warm N.A
-33-
4 5 6 7
Add 30 Sec. Quick Defrost Soften
5 6 Melt
Timer Sensor Reheat Less
Sensor Cook N.A More
Defrost
Time Cook Power Level
Turntable On/Off
RESULTS
When
When not
touched
touched
Resistance
value
More than
Less than
1 megaohm
400 ohms
FPC CONNECTOR
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