Motorola GP328 Detailed Service Manual

Troubleshooting charts 6E-29
Is information
from
mPU409
correct?
Is U205
Pin 18
Is U205
Pin 47
In receive, is
Pin1<.7VandPin2>
3 Vplus in transmit is
Pin1>3VandPin2<
.7 V?
Start
Visua l
check of the
Board OK?
Correct
Problem
Check 5V
Regulator
+5V at U205
Pin’s
13 & 30?
Is 17.0 MHz
Signal at
U205 Pin 19?
Check Y201,CR211,
C236,C237,C242,
R219
Signal
at Pin
16 of U205?
Replace U205
Replace or
resolder
necessary
components
Is RF level at
U205 Pin 32
>-30 dBm?
Are loop filter parts
R224,R225,R227,R
228,R229,C256,C2
57,C259 and C260
Replace U201
If R234, R238 & C297
are OK, then see VCO
troubleshooting chart
Do Pins 7,8 & 9
of U205 toggle
when channel is
changed?
Check programming
lines between U409
and U205 Pins 7,8 & 9
Replace U205
Check uP U409
Troubleshooting
Chart
NO
YES
NO
YES
NO
NO
YES
NO
YES
YES
NO
YES
YES
YES
NO
NO
NO
NO
YES
NO
YES
YES
Check C240, C247,
C246, C249, L223
and D201
3.3V at U205
pins 5, 20, 34
&36
Check U400
and L225
Is
17.0MHz
signal at
U201 pin
23?
Replace
U205
YES
NO
NO
YES
Troubleshooting Flow Chart for Synthesizer

Motorola GP328 Specifications

General

Channel Capacity	16 channels
Operating Temperature	-30°C to +60°C
Sealing	IP54
Frequency Range	136-174 MHz (VHF), 403-470 MHz (UHF)
Power Output	1-5W (VHF), 1-4W (UHF)
Dimensions	137 x 57.5 x 37.5 mm
Power Supply	7.5V
Battery Life	8 hours (High Power), 11 hours (Low Power) with standard NiMH battery
Weight	420g (with standard battery)