Motorola Commercial CM Series - Troubleshooting Flow Chart for Synthesizer.

Troubleshooting Flow Chart for Synthesizer 3-7
3.0 Troubleshooting Flow Chart for Synthesizer
5V
at pin 6 of
D200
Is
information
from mP U403
correct
?
Is
U200 Pin 47
at = 13VDC
?
Is
U201 Pin 19
<40 mVDC in RX &
>4.5 VDC in TX?
(at VCO section)
?
Start
Visual
check of the
Board
OK?
Correct
Problem
Check 5V
Regulator
U503
+5V
at U200
Pin’s
13 & 30
?
Is
16.8MHz
Signal at U200
Pin 19
?
Check
Y201 and associated
Parts
Are
signals
at Pin’s 14 &15
of U200
?
Check
R228
Check R201
Is
U200
Pin 2 >4.5 VDC in
Tx & <40 mVDC
in Rx
?
Replace U200
Remove
Shorts
Is
there a short
between Pin 47 and
Pins 14 & 15 of
U200
?
Is
RF level at
U200 Pin 32
-12 < x <-25
dBm
?
Replace U200
Are
Waveforms
at Pins 14 & 15
triangular
?
Do
Pins 7,8 & 9
of U200 toggle
when channel is
changed?
Check programming
lines between
U403 and U200
Pins 7,8 & 9
Replace U200
Check uP U403
Troubleshooting
Chart
NO
YES
NO
YES
NO
YES
NO
NO
NO
YES
YES
YES
NO
YES
YES
YES
NO
NO
NO
NO
YES
NO
YES
YES
Check D200, D201,
C2026, C2025, &
C2027
5V
at U200
pins 5, 20, 34
& 36
C h e c k 5 V
Regulator
U503
Is
16.8MHz
signal at
U200 Pin
23?
Replace
U200
YES
NO
NO
YES
NO
YES
If C2052, R208,C2067,
C2068, L210 are OK, then
see VCO
troubleshooting chart