Midland 70-1341, Service Manual

Page: 31 / 68

SERVICING
70-1341/1344/1441/1444
TROUBLESHOOTING CHARTS
4 - 7
YES NO
YES
YES
YES NO
NO
YES
No
transmit
or receive, but
display lights
up?
Troubleshooting Chart 3 – 1 — Getting Started
START
Error Code
Displayed?
Transmitter
Problem?
No
transmit,
receive or
channel
display?
Transmit
and receive
OK, but no
scan?
Receiver
Problem?
Transmit
Transmit and
receive OK, but
can’t change
channels?
and receive OK,
but display
blank or
incorrect?
DONE
Check EEPROM
Module (IC902). If
problem persists,
see Logic
Troubleshooting
Chart, page 4 – 12.
Replace faulty
fuse
Suspect IC901
Suspect
IC301
IC301
OK?
Fuse
F201 and
Mainline
Fuse OK?
Suspect IC204,
IC904, IC905
or IC910
Go to Error Code
Displayed
Troubleshooting
Chart, page 4 - 8
Go to Transmitter
Troubleshooting
Chart, page 4 - 9
Go to Receiver
Troubleshooting
Chart, page 4 - 10
Go to Logic
Troubleshooting
Chart, page 4 - 12
IC204,
IC904, IC905,
IC910 voltage
regulators
OK?
NO
YES
Go to Logic
Troubleshooting
Chart, page 4 - 12
+5 V on
IC901
pin 73?
NO
YES
NO
NO
NO
NO
YES
YES
YES
NO
NO
NO
YES
YES