Lowband Controller - Motorola GP360 Service Information

2-4
4.0

Lowband Controller

INT
AUDIO
NO
J403 Audio
at Pin 2 &
Pin 3
YES
Audio from Pin 41
Check Spk. Flex
Connection
Check NO
U303
LV ZIF
EXT
PTT
Radio could
not PTT
externally
OPT_SEL_1 &
EXT
SPKR
J403 Pin 9
low? Pin 8
high?
YES
ASFIC U404
Pin 14 & 15
high?
YES
Check
U420 Audio PA
PTT
Press PTT. Red
LED does not
Audio at
YES
AudioPA
(U420)
input
PTT U409
Check
Audio PA
(U420)
YES
NO
ASFIC, U404?
Press PTT
CR502-2
NO
Audio at
Pin 2
CR502-2
U404?
YES
Check
LED should
ASFIC U404
light up
J403
NO
Check
OPT_SEL_2 Accessories
Pin 8 & 9
low?
U409
YES
YES
Pin 52, 6
NO
low?
Check
NO
Accessories
NO
Check
U404
MCU Check
light up
Power Up
Alert Tone
NO
Pin 53
low?
Check
PB504
YES
High?
No
U409 EXTAL=
Check
7.3728 MHz?
voltage
LED,
YES
CR502,R501
OK?
U205 Pin 19
17.0MHz
NO
Replace
Faulty
Component
5V at U204?
Check
MCU
U409 Reset
See FGU
Troubleshoot-
ing chart
MCU is OK
TROUBLESHOOTING CHARTS
Not able to pro-
YES
gram RF Board
OK?
ICs
NO
NO
Replace
Speaker
Speaker
OK?
YES
YES
Read Radio
OK?
NO
NO
YES
7.5V at
NO
Pin 5 U204?
3.3V at
7.5V at Pin 8
U400?
U400
YES
NO Check any short
to SWB+,
Pin 94
Vdda or Vddd
High?
YES
Before replacing
MCU, check SPI
clock, SPI data,
and RF IC select
NO
Check
Setup
YES
Reprogram the
correct data.
See FGU
Troubleshooting
NO
Check
Q400
YES
Replace
U204/U400