Service Manual

73
Chart 10—Base-to-Portable Repeat Failure
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START
Verify that the VRS750
dip switches are set to
normal operation.
Activate the
VRS750.
Is "VRS
BOTH" displayed
briefly?
Provide an
on-channel RF
signal to the mobile.
The VRS750 is not
enabled and audio
will not be heard.
Is
audio present at
C135?
Is audio
present @ U101 pin
5?
Chekc mobile and
its connection to
the VRS.
Is audio
present @ U101 pin
4?
Check U104.
Adjust R150 if
necessary.
Is
audio present @
TP101?
Verify that the
local mic is not
pressed.
Is
audio present
@ J30-19?
Is pin 10
of U101 HIGH
-9.6VDC?
Is
there continuity
between J30-19 and
J20-7 of the flex
cable?
Replace the
transceiver.
Replace U101.
Is
there continuity
between J30-8 and
J40-23 on the flex
cable?
Is pin
9 of U101 low
(0VDC)?
Repair/replace
U101.
Is
there continuity
between J30-15 and
J40-23 on the flex
cable?
Replace the
transceiver.
Replace the flex
cable.
Check and/or
replace Q106.
Replace the flex
cable.
Repair/replace
Q114.
Replace the flex
cable.
BASE TO PORT. AUDIO ISSUES