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3-4
3.0
Troubleshooting Flow Chart for Synthesizer
Check D3201,
C3203, C3205, &
C3206
YES
Is
5V
NO
U1201 Pin 47
at pin 6 of
at = 13VDC
CR1202
NO
Check
R1218
Is
U1377, Pin 2
<.1VDC in RX &
>4.5 VDC in TX?
(at VCO section)
YES
Is
RF level at
U1201, Pin 32
-5 < x < 0 dBm
?
YES
Are
R1205, R1206,
R1208, C1212,
C1213 & C1214
OK?
YES
Replace
U1201
Correct
Problem
?
YES
Check C3319
NO
Is
YES
U1201 pin 2
>4.5 VDC in Tx &
<.1 VDC in Rx
?
NO
Replace
U1201
If Q1202
NO
Feedback Amp stage is OK,
Then see VCO
troubleshooting chart
Replace or
NO
resolder
necessary
components
Start
Visual
NO
check of the
Board OK
?
YES
+9.3V
NO
at U1201
Pin 30
?
Check 9.3V
R e g u l a t o r
U0641
Are
signals
at Pin's 14 &
15 of U1201
?
YES
Is
there a short
NO
between Pin 47 and
Pins 14 & 15 of
U1201?
YES
Remove
Shorts
Low Band TROUBLESHOOTING CHARTS
5V at
NO
U1201 pins 5,
13, 20, 24 &
36 ?
YES
Is
NO
16.8MHz
Signal at
U1201 Pin
YES
19?
YES
NO
Are
Waveforms
at Pins 14 & 15
triangular
?
YES
NO
Check programming
lines between U0101
and U1201 Pins 7,8 & 9
NO
Check uP U0101
Troubleshooting
Chart
Check 5V
Regulator U1250,
L1201 & R1201
Is
16.8MHz
Replace
signal at
U1201
U1201 Pin
YES
23?
NO
Check Y1201,
C1204,
C1206,C1207,
CR1201. & R1203
NO
Do
Pins 7,8 & 9
of U1201 toggle
when channel is
changed
?
YES
Is
information
u
from
P U0101
correct?
YES
Replace
U1201
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Troubleshooting
