Troubleshooting Flow Chart For Transmitter - Motorola GM328 Service Manual

Troubleshooting Flow Chart for Transmitter

2.0 Troubleshooting Flow Chart for Transmitter
No
DC Voltage
@Drains of
Q1402 &
Q1403
Look for
Yes
short on
Supply Line
No DC Voltage
@ Cathode of
D1401 &
D1402
Check 9T1 and
Yes
Diode Bias Circuit
No
AC Voltages @
Drains of Q1402 &
Q1403 both sine or
both distorted
Verify RF Continuity
to gates of
Yes
Q1402 & Q1403
Check circuitry
between Q1402 &
Q1403 and
Antenna Port
START
No or Low
Power Out
TX
No
Safefy
Switch
Yes
> 1 A
< 1 A
TX
CURRENT
R1413 & R1414
No
Check
DC Voltage
MOSBIAS_2
@ TP1402 &
MOSBIAS_3
and Feed Networks
Check DC/AC
Gate Circuits
of Q1402 & Q1403
Check Pressure Pad
and/or
Switch Circuitry
<<18V pp
RF @
Junction
DC Voltage
@ Gate of
Q1401
>18V pp
AC Voltage
@ Gate of
TP1403
Q1401
Yes
DC Voltage
@ U1401
Check Supply Feed
and/or PowerControl
Circuits.
No
Check
MOSBIAS_1
Supply and
Feed Network
Yes
Yes
Check
Q1401
Device
No
Yes
Check
U1401
Device
No
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