Panasonic KX-F900 Service Manual page 37

KX-F900 1
C_ Unit can copy, but can not transmiUreceive
Check solder at-thee--- _
pin 8 of IC10 and Q8.
NO
Connect the unit to the
loop simulator.
Switch : TX side T-R
: Connect oscilloscope
l
Modem test start
(TEST CODE NO. 554)
1
Is the four signal at
Tip-Ring output?
1"°
Is the signal at pins
44 of ICl 1 output?
Is the voltage at pin 8
of IC10 24 V?
YES
___connect the PBX and
l
EL. line and off-hook.
J
YES
YE_S Check the trace
between pins 44 of
IC11 and Tip-Ring.
Check the trace
between T1 and pin
45 of IC11.
-I
O
(:
r-
m
.1-
O
O
-I
z
D
L
_o_ tl h l lii_a_ It:tn iin-_ i _
I YES
Replace IC11. J
Check the solder at
pins 116 of IC1.
l
Replace IC11.