Keypad Back-Light Illumination - LG KE820 Service Manual

3. TECHNICAL BRIEF
Most of numeric keys are located on the sub PCB, Jog key for menu navigation is on the main PCB,
and Power on (End key), MP3 hot key, Camera AF trigger, shutter and volume up & down keys are
connected via 50pin board to board connector between main PCB and FPCB.

3.9. Keypad back-light illumination

There are 7 snow white color LEDs on the sub PCB for keypad illumination. Keypad Back-light is
controlled by SM-Power LED port which has constant current control function.
The whole configuration of the SM-POWER LED drivers is shown in below Figure16. ( SLED1, SLED2
port are not used in the KE820.KG99)
KP_IN(2:5)
KP_IN(2)
KP_IN(3)
KP_IN(4)
KP_IN(5)
KP_OUT(3:4)
KP_OUT(3)
KP_OUT(4)
Figure 14 FPCB part key matrix
- 44 -
END
END_KEY
V_UP
V_DOWN
MP3
SW1
1 4
shutter
AF
2 3
VBAT