LGE Internal Use Only
Copyright © 2007 LG Electronics. Inc. All right reserved.
Only for training and service purposes
3.11.6 Folder ON/OFF Operation
There is a magnet to detect the Folder status, opened or closed.
If a magnet is close to the hall-effect switch, the voltage at pin1 of U504 goes to 0V. Otherwise, 2.6V.
This folder signal is delivered to MSM6275 GPIO43.
3.11.7 Keypad Light
There are 16 White LEDs in Main board backlight circuit, which are driven by KYBD_BACKLIGHT line
from PM6650.
3. TECHNICAL BRIEF
- 56 -
Figure. Schematic of Folder ON/OFF detection circuit
(For Hall Sensor)
0.01u
C489
VREG_MSMP_2.7V
R504
100K
62
R402
0.1uF
C410
3
GND1
GND2
4
2
NC1
5
NC2
1
OUTPUT
7
PGND
6
VDD
U504
A3212EEH-T
FOLDER_DETECT
Figure. Keypad Backlight Circuit
KEY_BACK_LIGHT
LD525
LD523
R451
100
LD527
R457
100
R1045
100
LD507
R452
100
R1044
100
100
R466
100
R465
LD510
100
R469
100
R467
R458
100
R456
100
LD511
LD514
100
R472
100
R495
LD506
VA515
EVL14K02200
LD515
R459
100
LD513
100
R468
100
R471
LD509
LD526
LD524
LD522
LD521
LD520
KYBD_BACKLIGHT
+VPWR
Summary of Contents for TU550
Page 1: ...Date May 2007 Issue 1 0 Service Manual Model TU550 Service Manual TU550 Internal Use Only ...
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