Motorola GP328 Plus, Service Manual

Page: 87 / 206

Troubleshooting Charts 5A-31
9.0 Troubleshooting Charts
MCU Check
Power Up
Alert Tone
OK?
Speaker
OK?
U409 EXTAL=
7.3728 MHz?
U3701 Pin 19
16.8 MHz
5V at U3711?
3.3V at U3201?
U409 Reset Pin
94 High?
MCU is OK
Not able to pro-
gram RF Board
ICs
Before replacing
MCU, check SPI
clock, SPI data, and
RF IC select
Replace Speaker
Read Radio OK?
Check
Setup
Reprogram the
correct data.
See FGU
Troubleshooting
7.5V at
Pin 3/5 U3711?
7.5V at Pin 1
U3201
Check
Q400
Replace U3711/
U3201
Check any short to
SWB+,
Vdda or Vddd
Press PTT. Red
LED does not
light up
PTT U409 Pin
53
low?
Press PTT
Q502-2 High?
Check
PB504
Check
Q502-2
voltage
LED
Q502,R501
OK?
Replace
Faulty
Component
Check
Accessories
J403 OPT_SEL_1
& OPT_SEL_2
Pin 8 & 9
low?
Radio could
not PTT
externally
U409
Pin 52, 6
low?
See FGU
Troubleshooting
chart
LED should
light up
Check
MCU
PTT
NO
YES
YES
No
No
NO
YES YES
NO
YES
YES
NO
NO
YES
YES
NO
NO
YES
NO
YES
NO
YES
YES
NO
NO
YES
EXT
SPKR
EXT
PTT
INT
AUDIO
J403 Pin 9 low?
Pin 8 high?
ASFIC U404 Pin
14 & 15 high?
Check
Accessories
Check
U404
Check
U420 Audio PA
NO
NO
YES
YES
J403 Audio
at Pin 2 &
Pin 3
Check Spk. Flex
Connection
Audio at
AudioPA
(U420) input
(U447)
Audio from Pin 41
ASFIC, U404?
Check ASFIC
U404
Check
Audio PA
(U420)
Check
U3220
LV ZIF
Audio at
Pin 2
U404?
NO
NO
NO
YES
YES
NO
YES
Troubleshooting Flow Chart for Controller