Samsung AW0690A Service Manual page 32

5-2-2 When the MEMBRANE KEY PAD AND LED DISPLAY
1) Check points
(1) Is the voltage of the power source normal ? (the rating voltage ±10% range.)
(2) Is the electric wire in good contact ?(CN71, RY71)
(3) Is the connection of the assembly main PCB, and MEMBRANE KEY PAD in good contact?
(CN91)
N
Normal operation
Check the micom
N
(IC04) for a short,
and replace it.
Check the micom
N
(IC04) for a short,
and replace it.
Check the Q901~
N
Q905 for a short,
and replace it.
Check the IC07
N
for a short, and
replace it.
Samsung Electronics
Turn off the power, and then turn it on again
five seconds later.
When the LED DISPLAY is
not operated.
Y
Is the voltage of the micom
(IC04) No.1, 2, 38~43 port a
square wave?
Y
Is the voltage of the micom
(IC04) No.3, 4, 10, 11, 44 port a
square wave?
Y
Is the voltage of the
Q901 ~ Q905 square wave?
Y
Is the voltage of the
IC07 No. 10~16 a square value?
Y
Replace the MEMBRANE KEY PAD
When the MEMBRANE KEY
is not operated.
Y
Is the voltage of the
micom (IC04) No.13, 14 port
a square wave?
Y
Is the voltage of the micom
(IC04) No.3, 4, 10, 11, 44 port a
square wave?
Y
Replace the MEMBRANE
KEY PAD.
Troubleshooting
N
Normal operation
Check the micom
N
(IC04) for a short,
and replace it.
Check the micom
N
(IC04) for a short,
and replace it.
5-3