Samsung SGH 600, Service Manual

Page: 28 / 74

5-8 Samsung Electronics
Troubleshooting
KEY DATA INPUT
Check Initial operation
Does
the scanning Signals
come out from pin 140, 141, 142,
143, and 144 of
U408?
Resolder pin 140, 141, 142, 143
and 144 of U408 (kernel)
Check the bad contact on any key and
clean the keypad area on the B’D
Resolder U408 pin 1, 2, 3, 4 and 5
Is the key data input OK?
END
No
Yes
No
Yes