Key Sense Trouble (Keypad) - LG KF690 Service Manual

4. TROUBLE SHOOTING

4.4 Key sense trouble (KEYPAD)

Key Sense sequence of KF690 is :
Default condition ROW(0-3) is 2.7V
→
Scan pulse( Col => Row )
LGE Internal Use Only
→ →
Press the key
→
MSM sense what key pressed.
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Corresponding ROW(x) and COL(x) go to 0V
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