LGE Internal Use Only
Copyright © 2007 LG Electronics. Inc. All right reserved.
Only for training and service purposes
4. TROUBLE SHOOTING
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4.11 Keypad backlight trouble
Key Pad Back Light is on as below :
Key pressing
→
STn8810 commend MSM6275 lighting the Key LED
→
MSM 6275 KPD_DRV_N go to Low
→
LED On (Key Pad LED controlled by PM6650)
Start
Check device short :
LD400~407 and R402~412 (Main)
LD101~108 and R106~114 (Sub)
NO
Yes
Yes
Key press
Signal KPD_DRV_N
is Low?
AP_+VPWR is OK?
Check connection
between Main and FPCB
and between FPCB and Sub
NO
Only Sub board LED
is not work?
Change the main board
NO
Yes
Yes
Check device open :
LD400~407 and R402~412 (Main)
LD101~108 and R106~114 (Sub)
NO
Some LED
is not work?
Work well?
Yes
Change the main & Sub board
NO
En d
LD400~407 and R402~412 (Main)
LD101~108 and R106~114 (Sub)
R400 (AP_+VPWR)
VA400 (KPD_DRV_N)
Summary of Contents for KS10
Page 1: ...Date July 2007 Issue 1 0 Service Manual Model KS10 Service Manual KS10 Internal Use Only ...
Page 246: ...Note ...
Page 247: ...Note ...