Panasonic KX-F680BX - Page 32

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TROUBLESHOOTING GUIDE
KX-F680BX/KX-F2681BX
Check solder at the
pin 8 of IC10 and Q5.
Connect the unit to the
loop simulator.
Switch : TX side T-R
: Connect oscilloscope
Modem test start
Is the four signal at
Tip-Ring output?
Connect the PBX and
TEL. line and off-hook.
Check the trace
between pins 28, 29 of
IC5 and Tip-Ring.
Is the signal at pin 38
of IC5 dial tone input?
Replace IC5.
Check the trace
between T1 and pin
38 of IC5.
Is the signal at pins
28, 29 of IC5 output?
Is the voltage at pin 8
of IC10 24 V?
Check the solder at
pins 116 of IC1.
Replace IC5.
OK
3 Unit can copy, but can not transmit/receive
YES
YES
YES
YES
NO
NO
NO
NO
(TEST CODE NO. 554)