Samsung SCH-3500 series Service Manual page 37

Trouble Shooting
8-1-5 Abnormal Key tone
Abnormal keytone.
CLK waveform
outputted from U908
pin 189?
CLK waveform
applied from U902
pin 2~3?
CLK waveform applied
to C907 R932?
Normal key tone?
END
NO
YES
NO
YES
NO
YES
NO
YES
SAMSUNG Proprietary-Contents may change without notice
Check U908 pin 189. Replace if required.
Replace U902
Check C907, R932
Replace the Keypad assembly.
8-5