Troubleshooting And Repair . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Section F How To Use Troubleshooting Guide - Lincoln LN-742 Service Manual

SECTION F-1
Troubleshooting And Repair . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Section F
How To Use Troubleshooting Guide . . . . . . . . . . . . . . . . . . . . . . . . . . .
PC Board Troubleshooting Procedures . . . . . . . . . . . . . . . . . . . . . . . . .
Troubleshooting Guide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Test Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Tachometer Feedback Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Drive Motor Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Input Voltage Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Keypad Resistance Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Component Replacement Procedures . . . . . . . . . . . . . . . . . . . . . . . . .
Wire Drive Assembly and Components Replacement . . . . . . . . . . .
Swing Arm Assembly Replacement for Two-Roll Wire Feeders . . . .
Swing Arm Assembly Replacement for Four-Roll Wire Feeders . . .
Gas Solenoid and Connections Replacement . . . . . . . . . . . . . . . . .
Retest After Repair . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Check Wire Feed Speed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
TROUBLESHOOTING AND REPAIR
TABLE OF CONTENTS
-TROUBLESHOOTING AND REPAIR-
ELECTRIC SHOCK can kill.
• Never work on the inside of the machine without turning off the input
power. You can receive a life threatening electrical shock if you fail to
do this. Only qualified technicians should perform installation,
maintenance, and troubleshooting work on the machine.
LN-742 & LN-742H
WARNING
SECTION F-1
F-2
F-3
F-4
F-10
F-10
F-12
F-14
F-18
F-22
F-22
F-26
F-28
F-31
F-34
F-34