
— 19 —
6. Voice cannot be transmitted to other party (outgoing call).
Can the base and handset be
connected?
See 3. The base and handset
cannot be connected.
OK
NG
T h e 1 k H z , 9 . 0 m V s i n e
wave fo r m i s a p p l i e d t o
MC601 + side, can the 1 kHz
sine waveform from pin 24 of
IC601 be fed?
Check Q604 and its
peripheral circuit.
NG
Check whether there is the
1 kHz sine wavefor m at
pin 20 of IC601.
Check IC601 and its
peripheral circuit.
NG
OK
OK
Check whether there is the
1 kHz sine wavefor m at
C669.
Check RT603 and its
peripheral circuit.
NG
OK
TX output signal from the
handset is detected by the
liner detector, can the 1 kHz
sine waveform be fed?
Check handset RF unit.
NG
OK
Check whether there is the
1 kHz sine waveform at pin 9
of IC3 on the base unit.
Check IC3, Q1 and their
peripheral circuit.
NG
OK
Check whether there is the
1 kHz sine waveform at pin 3
of IC1.
Check RT2, Q2 and their
peripheral circuits.
NG
OK
Check whether there is the
1 kHz sine wavefor m at
pin 18 of IC1.
Check IC1 and its
peripheral circuit.
NG
OK
Check whether there is the
1 kHz sine waveform at the
Q3 collector.
Check Q3 and its
peripheral circuit.
NG
OK
Check whether the 1 kHz sine
wavefor m from TEL-line
output is fed.
Check T1, RL1 and their
peripheral circuits.
NG
OK
Check MC601 of handset.
Check base RF unit.
NG
OK
Summary of Contents for FT-8981
Page 1: ...SERVICE MANUAL PUBLISHED IN JAPAN May 2001 FILE NO 2B0 200104 FT 8981 CORDLESS TELEPHONE ...
Page 9: ... 8 BLOCK DIAGRAMS Base Unit ...
Page 10: ... 9 Handset ...
Page 12: ...Handset 12 13 FT8981 Sche p65 01 05 25 13 21 Page 9 Adobe PageMaker 6 5J Win ...
Page 27: ... 28 ELECTRICAL PARTS LOCATION Base Unit Main PCB ...
Page 28: ... 29 Handset Main PCB ...
Page 29: ... 30 WIRING DIAGRAMS Base Unit ...
Page 30: ... 31 Handset ...