Troubleshooting Flow Chart For Synthesizer - Motorola HT Series Detailed Service Manual

UHF Troubleshooting Charts: Troubleshooting Flow Chart for Synthesizer
3.5

Troubleshooting Flow Chart for Synthesizer

Correct
Check CR201,
U210, U211, C258, Problem
C259 & C228
YES
5V
Is U201 Pin
NO
at pin 6 of
47AT = 13
CR201
VDC
NO
YES
Check
L202
Is U241 Pin 19
<0.7 VDC in RX &
>4.3 VDC in TX?
YES
NO
Is U201 Pin
18 AT 4.54
VDC?
YES
Is RF level at
U201 Pin 32
>-30 dBm?
YES
Are R231,R232,
R233,C231,C232,
& C233 OK?
YES
Replace U201
FMR-2045A-2
NO
Check Q260,
Q261 & R260
Check 5V
Regulator
NO
YES
U201 pin 2 at
>3V in Tx and
<0.7V in Rx
NO
NO
Replace U201
If L261, C263 & C264
NO
are OK, then see VCO
troubleshooting chart
Replace or
NO
resolder
necessary
components
3.3V at U201
Start
pins 5, 20, 34
Visual
check of the
Board OK?
YES
U201 Pin 19?
YES
+5V at U201
NO
Pin's
13 & 30?
YES
NO
Are signals
at Pin's 14 &
15 of U201?
YES
Is there a short
between Pin 47 and
Pins 14 & 15 of
U201?
YES
Remove
Shorts
NO
Check U248,
L201 & L202
& 36
YES
Is
Is 16.8MHz NO 16.8MHz
Signal at signal at
U201 pin
YES
23?
NO
Check FL201, C206,
C207, C208, CR203
& R204
NO
Are Waveforms
at Pins 14 & 15
triangular?
YES
Do Pins 7,8 & 9
NO
of U201 toggle
when channel is
changed?
Check programming
lines between U409
YES
and U201 Pins 7,8 & 9
NO
Is information
µ
from P U409
correct?
Check uP U409
Troubleshooting
YES
Chart
Replace U201
December 26, 2003
35
Replace
U201