Service Manual

71
Chart 8—Single Tone Encode Failure
No
No
No
Ye s
No
Ye s
No
Ye s
No
Is there
continuity between
J30-19 and J20-7 on the
flex cable?
Check and/or
replace C104.
Replace the
transceiver.
Replace the flex
cable.
Replace the
transceiver.
Replace the flex
cable.
START
SINGLE TONE ENCODE FAILURE
Ye s
Ye s
Ye s
Is
3.3VDC square wave
at R114 during Single
Tone burst?
Is
80mVpp sinewave
at TP104?
Is
there continuity
between J30-6 and
J40-21 on the flex
cable?
Is the
sinewave present at
TP101?
Check and/or
replace U100,
U124.
Is
the sinewave
present at the negative
terminal of C104?
Verify that pin 10 of U101 is
0VDC during the Single
Toneburst. Check U101 and
Q106.