Key Sense Troubleshooting - LG KU730 Service Manual

4. TROUBLE SHOOTING

4.12 Key Sense Troubleshooting

Key Sense sequence of KU730 is :
Default condition ROW(0-4) is 2.6V -> Press the key -> Corresponding row(x) go to 0V -> Key
sensing
CN600, CON600
ROW[0-3]
RA600
R605
Start
Check the side key
CN600,CON600
Work well?
NO
Check the Key PCB
YES
ROW(0-4) is 2.6V?
YES
Check the CN600?
NO
Change the Main board
- 102 -
Yes
End
NO
Change the Key PCB
NO
Check RA600 And R605
Yes
Change the Main board
COL[2-4]