Qwerty Key Sense Trouble - LG GW520 Service Manual

5.6 Qwerty Key Sense Trouble

Start Start
Change the Dome Sheet Change the Dome Sheet
And check again. And check again.
Work well? Work well?
END END
Circuit Diagram Circuit Diagram
KEY_COL7
KEY_COL6
KEY_COL5
KEY_INT
KEY_I2C_SCL
Copyright © 2009 LG Electronics. Inc. All right reserved.
Only for training and service purposes
Check TP1 soldering Check TP1 soldering
& signaling. OK? & signaling. OK?
Work well? Work well?
2V62_VIO
1
TEST
2
SEL_28P
R410 470
3
P57
R414 470 4
P56
R418 470 5
P55
6
P17
7
P15
TP1
VA401
EVLC5S0250
VA402
EVLC5S0250
C417 27p
C418 27p
C419 27p
GW520 service manual
2V62_VIO
TP1
KEY_I2C_SDA
21
P40
20
P41
19
P42
U400
18
P43
17
P44
EUSY0300004
16
PP2106M2 P45
15
P46
VA400
EVLC5S0250
- 81 -
5. Trouble shooting
Check TP2 soldering Check TP2 soldering
& signaling. OK? & signaling. OK?
Re-solder R621,R622, Re-solder R621,R622,
R637, R639 R637, R639
R404 470
KEY_ROW0
R407 470
KEY_ROW1
R411 470
KEY_ROW2
R415 470
KEY_ROW3
R419 470
KEY_ROW4
R422 470
KEY_ROW5
R425 DNI
TP2
LGE Internal Use Only