TROUBLESHOOTING CHARTS
2-5
IF Signal
at L3200?
No
RF
Signal at
T3301?
RF
Signal at
R3313?
No
RF
Signal at
C3302?
No or
Check harmonic filter L3531 & L3532,
C3532 and ant. switches D3521, D3551,
L3551, R3551, C3551, C3552, L3552
Check filter between
C3302 & C3306; pro-
gram filter to schematic
test freq and check
varactor voltages.
Inject RF into J3501
Are varactor
voltages OK?
No
Yes
Check RF amp (Q3302)
Stage.
Check filter between
C3313 & T3301.
Yes
Check T3301, T3302,
CR3301, R3321, R3322,
R3323
Yes
1st LO O/P
OK?
Locked?
Yes
Check FGU
Yes
Trace IF signal
from L3200 to
Q3200. Check for
bad XTAL filter.
No
Yes
Q3200
collector OK?
IF signal
present?
Before replacing
U3220, check
U3220 volt-
ages; trace IF
signal path.
Yes
Check for 2.9
VDC
Is R5
present?
Check Q3721,
U3701 (pin 48)
voltages and U247
No
No
No
Check U404 voltage and if
U404 can be selected by
MCU before replacing
U404.
Check varactor filter.
No
Yes
Yes
Yes
A
A
B
weak RF
RF
Signal at
C3306?
Figure 2-4
Troubleshooting Chart for Receiver (PCB 8415533H02) (Sheet 2 of 2)
Summary of Contents for GP-688
Page 5: ...Compact Professional Portable Radios Service Maintainability Issue July 2007 ...
Page 14: ...x THIS PAGE INTENTIONALLY LEFT BLANK ...
Page 24: ...2 6 MAINTENANCE THIS PAGE INTENTIONALLY LEFT BLANK ...
Page 32: ...3 8 SERVICE AIDS THIS PAGE INTENTIONALLY LEFT BLANK ...
Page 34: ...4 2 POWER UP SELF TEST THIS PAGE INTENTIONALLY LEFT BLANK ...
Page 38: ...iv THIS PAGE INTENTIONALLY LEFT BLANK ...
Page 52: ...2 10 TROUBLESHOOTING CHARTS THIS PAGE INTENTIONALLY LEFT BLANK ...
Page 64: ...3 12 CONTROLLER KEYPAD SCHEMATICS ...
Page 112: ...3 60 PCB and Schematic Drawings IP67 THIS PAGE INTENTIONALLY LEFT BLANK ...
Page 116: ...3 64 PCB and Schematic Drawings IP67 THIS PAGE INTENTIONALLY LEFT BLANK ...
Page 120: ...3 68 PCB and Schematic Drawings IP67 THIS PAGE INTENTIONALLY LEFT BLANK ...
Page 147: ...Compact Professional Portable Radios VHF 136 174MHz Service Information Issue July 2007 ...
Page 150: ...iv ...
Page 172: ...2 10 TROUBLESHOOTING CHARTS THIS PAGE INTENTIONALLY LEFT BLANK ...
Page 176: ...3 4 THIS PAGE INTENTIONALLY LEFT BLANK ...
Page 192: ...3 20 VHF PCB Schematic Diagrams THIS PAGE INTENTIONALLY LEFT BLANK ...
Page 240: ...iv THIS PAGE INTENTIONALLY LEFT BLANK ...
Page 258: ...2 8 TROUBLESHOOTING CHARTS THIS PAGE INTENTIONALLY LEFT BLANK ...
Page 284: ...3 26 UHF1 PCB and Scematics Diagrams THIS PAGE INTENTIONALLY LEFT BLANK ...
Page 288: ...3 30 UHF1 PCB and Scematics Diagrams THIS PAGE INTENTIONALLY LEFT BLANK ...
Page 302: ...3 44 UHF1 PCB and Schematic Diagrams THIS PAGE INTENTIONALLY LEFT BLANK ...
Page 312: ...3 54 UHF1 PCB and Schematic Diagrams THIS PAGE INTENTIONALLY LEFT BLANK ...
Page 318: ...3 60 UHF1 PCB and Schematic Diagrams THIS PAGE INTENTIONALLY LEFT BLANK ...
Page 335: ...Compact Professional Portable Radios UHF2 450 527MHz Service Information Issue July 2007 ...
Page 338: ...iv THIS PAGE INTENTIONALLY LEFT BLANK ...
Page 348: ...1 10 THEORY OF OPERATION THIS PAGE INTENTIONALLY LEFT BLANK ...
Page 356: ...2 8 TROUBLESHOOTING CHARTS THIS PAGE INTENTIONALLY LEFT BLANK ...
Page 360: ...3 4 UHF2 PCB SCHEMATICS PARTS LISTS THIS PAGE INTENTIONALLY LEFT BLANK ...
Page 374: ...3 18 UHF2 PCB and Schematic Diagrams THIS PAGE INTENTIONALLY LEFT BLANK ...
Page 378: ...3 22 UHF2 PCB and Schematic Diagrams THIS PAGE INTENTIONALLY LEFT BLANK ...
Page 388: ...3 32 UHF2 PCB and Schematic Diagrams EPP THIS PAGE INTENTIONALLY LEFT BLANK ...
Page 402: ...3 46 UHF2 PCB and Schemtaic Diagrams THIS PAGE INTENTIONALLY LEFT BLANK ...