LG LMVH1750SB Service Manual page 29

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 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)
2
1 3
1
2 3
8
CUSTOM
N.C N.C
COOK
9
(VENT) (VENT) LIGHT
5-SPEED
ON/OFF ON/OFF
10
POPCORN COOK REHEAT
DEFROST
11
CUSTOM AUTO TURNTABLE
SET COOK ON/OFF
12
POWER STOP/
N.C
LEVEL CLEAR
13
7-18
4 5
6
4 5 6 7
MICRO. CONV. N.C COMBI.
AUTO
N.C SOFTEN MELT
TIME SET
SPEED
AUTO
N.C
AUTO
EZ-ON
COMBI.
TIMER CLOCK MORE LESS
START/
8 9 0
ENTER
RESULTS
When
touched
Resistance
value
Less than
400 ohms
FPC CONNECTOR
Top
7
When not
touched
More than
1 mega ohm
1
2
3
4
5
6
7
8
9
10
11
12
13