Lcd Display Trouble - LG KE970 Service Manual

5. Trouble shooting

5.4 LCD display trouble

Check Points
-LCD assembly status ( FPCB)
-Connector combination
MIC1_P
MIC1_N
70pin FPCB connector
CN501
1
2
3
VMICP
4
VMICN
5
6
L501 270nH
C504 C505
7
270nH 15p 47p
L502
8
9
SPK_RCV_P
10
SPK_RCV_N
11
12
SCROLL_KEY_A
13
SCROLL_KEY_B
14
END_KEY
15
SLED1
16
17
18
DIF_RESET
19
20
LCD_ID
21
22
LCD_BACKLIGHT
23
L_WR
24
L_CD
25
L_CS
26
27
VBAT
KEY_BACKLIGHT
28
29
30
31
C507
32
2V72_IO
1u
33
34
35
C508
1u
At first check the LCD
back light enable
signal
LCD connector
- 78 -
70
KP_IN(0:5)
69
68
KP_IN(0)
67
KP_IN(1)
66
KP_IN(2)
65
KP_IN(3)
64
63
KP_IN(4)
KP_OUT(0:4)
62
KP_IN(5)
61
KP_OUT(0)
60
KP_OUT(1)
59
KP_OUT(4)
58
KP_OUT(2)
57
KP_OUT(3)
56
LCD_VSYNC
55
SLIDE_KEY_BACKLIGHT
54
L_D(0:7)
53
L_D(0)
52
L_D(1)
51
L_D(2)
50
L_D(3)
49
48
L_D(4)
47
L_D(5)
46
L_D(6)
45
L_D(7)
44
43
LCD_IF_MODE
42
FLASH_EN
41
SCROLL_EN
40
HALL_EN
39
38
37
MOTOR_N
36