3-2
TROUBLESHOOTING CHARTS
1.1
Troubleshooting Flow Chart for Receiver (Sheet 2 of 2)
IF
Signal at
C3101?
No
RF
Signal at
T4051?
RF
Signal at
C4015?
No
No
RF
Signal at
C4025?
No or
Check harmonic filter
L4491-L4493, C4492, J4401
and ant.switch
D4471, D4472, L4472.
Check filter between
C4025 & C4009.
Check tuning voltage
at R4060.
Inject RF into J4401
Is
tuning voltage
OK?
No
Yes
Check RF amp (Q4003)
Stage.
Check filter between
C4015 & T4051.
Yes
Check T4051, T4052,
D4051, R4052, L4008.
Yes
1st
LO level OK?
Locked?
Yes
Check FGU
Yes
Trace IF signal
from C3101 to
Q3101. Check for
bad XTAL filter.
No
Yes
IF
signal at Q3102
collector?
Before replacing
U3101, check
U3101 voltages.
Yes
Check for
5VDC
Is 9V3
present?
Check Supply Voltage
circuitry. Check Q0681,
U4211 and U0641.
No
No
No
Check U4501.
Check varactor filter.
No
Yes
Yes
Yes
A
A
B
weak RF
RF
Signal at
C4009?
Summary of Contents for 6864115B62-C
Page 1: ...Professional Radio GM Series Detailed Service Manual 6864115B62 C ...
Page 2: ...ii ...
Page 4: ...iv ...
Page 5: ...Professional Radio GM Series Service Maintainability Issue July 2007 ...
Page 8: ...ii ...
Page 22: ...2 10 MAINTENANCE ...
Page 25: ...Professional Radio GM Series Controlhead Service Information Issue July 2007 ...
Page 77: ...Professional Radio GM Series Controller Service Information Issue May 2007 ...
Page 100: ...2 2 TROUBLESHOOTING CHARTS ...
Page 104: ...3 4 Controller schematics parts list ...
Page 154: ...3 52 Controller T12 Schematic Diagrams ...
Page 155: ...Professional Radio GM Series VHF 136 174MHz Service Information Issue May 2007 ...
Page 164: ...1 6 MODEL CHART AND TECHNICAL SPECIFICATIONS ...
Page 176: ...2 12 THEORY OF OPERATION ...
Page 186: ...3 10 TROUBLESHOOTING CHARTS ...
Page 190: ...4 4 VHF PCB SCHEMATICS PARTS LISTS ...
Page 252: ...4 66 VHF 1 25W PCB 8471235L02 Schematics VHF 136 174 MHz IF ...
Page 256: ...4 70 VHF 1 25W PCB 8471235L02 Schematics ...
Page 257: ...Professional Radio GM Series UHF 403 470MHz Service Information Issue May 2007 ...
Page 266: ...1 6 MODEL CHART AND TECHNICAL SPECIFICATIONS ...
Page 366: ...2 12 THEORY OF OPERATION ...
Page 372: ...3 6 Low Band TROUBLESHOOTING CHARTS ...