Motorola MTX series Theory/Troubleshooting Manual

45
TROUBLESHOOTING FLOW CHART #6B
(800/900MHz, Open Architecture, No Receive Audio)
No/Low Audio
Check
Audio J301
Pins 10 & 12
Check U3
and
U3 Circuitry
NO
YES
MAEPF-23446-O
ILLUSTRATOR DATE
LETTERING SIZE:
REQUIRES:
EDITOR DATE
SW
Receive Audio 800/90 Troubleshooting Chart
3/19/93
Check
Audio J704
Pins 10 & 12
Replace
Jumper Flex
NO
Check
Audio
U701 Pin J7
Check
Replace
R761, C709,
& C792
Inject on Freq.
-47dBm Modulated
Carrier
NO
YES
Check
Audio
U601 Pin E4
Check
Replace
C607
Check
Audio
U701 Pin J4
Check
Audio
U601 Pin F4
Check
DC Voltage
U701 Pin C2
Check
DC Voltage
Q701
Collector
Check Continuity
from Q701
Collector to U701
Pin C2
Check
DC Voltage
U601 Pin B3
and C4
NO
HearClear
Radios Only
NO
YES
NONONO
Check
DC Voltage
U702 Pin F5
Check
DC Voltage
U702
Pins B5,
C5
Go to DC
Chart 3B
Replace
U702
Check
Replace
Q701
YES
YES
NO
NO
NO
Replace
U701
Check
Replace
C723, R804,
& C805
Replace
U702
YES
Check
Audio
U702 Pin C6
Check
Audio
U702 Pins A3,
A5, B2
NO
NO
Check
DC Voltage
U702 Pin C1
Check
Replace
Speaker,
Speaker Flex
Check Continuity
from U702,
Pin C1 to
U701 Pin B4
NO
YES
YES
YES
YES
Check
Audio
U701 Pin H6
Check
Audio
U601 Pin C1
Check
Audio
U701 Pin J5
YES
YES
YES
YES
YES
Replace U601
Check
Replace
C605
Check
Replace
C618, U701
Check
Replace
C608, U601
NO
NO
NO
YES
Check Continuity
from U601 Pin B3
to U712 Pins 5, 6,
7, and 8
JWB 3/22/93
YES

Motorola MTX series Specifications

General

Brand	Motorola
Model	MTX series
Category	Portable Radio
Language	English