Troubleshooting Charts
9B-51
IF Signal at
C3200?
No
RF Signal at
T3301?
RF Signal at
R3313?
No
RF Signal at
C3306?
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 var-
actor 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 C3200 to
Q3200. Check for
bad XTAL filter.
No
Yes
Q3200 collec-
tor 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) volt-
ages and U3711
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
Troubleshooting Flow Chart for Receiver (Sheet 2 of 2)
Summary of Contents for GP88s
Page 1: ...November 2003 GP88s Portable Radio Service Manual 6804111J47 D ...
Page 4: ...iv Document History THIS PAGE INTENTIONALLY LEFT BLANK ...
Page 16: ...xvi 4 0 Parts List for Speaker Mic Assembly 0104008J99 10 2 Glossary of Terms G 1 ...
Page 28: ...3 6 Programming Test Cable THIS PAGE INTENTIONALLY LEFT BLANK ...
Page 52: ...5 6 Test Mode THIS PAGE INTENTIONALLY LEFT BLANK ...
Page 56: ...6 4 Cloning Information THIS PAGE INTENTIONALLY LEFT BLANK ...
Page 60: ...7 4 Controller Board THIS PAGE INTENTIONALLY LEFT BLANK ...
Page 180: ...9B 48 Circuit Board Schematic Diagrams and Parts List THIS PAGE INTENTIONALLY LEFT BLANK ...