Lincoln Electric DC-400 Welder User Manual


 
E-4
TROUBLESHOOTING
E-4
Observe all Safety Guidelines detailed throughout this manual
If for any reason you do not understand the test procedures or are unable to perform the tests/repairs safely, contact your
Local Authorized Field Service Facility for technical troubleshooting assistance before you proceed.
CAUTION
PROBLEMS
(SYMPTOMS)
POSSIBLE
CAUSE
RECOMMENDED
COURSE OF ACTION
OUTPUT control not functioning on
REMOTE control.
Poor arc striking with semiautomat-
ic or automatic wire feeders.
Poor arc characteristics.
ARC CONTROL has no effect in
CV (FCAW/GMAW) mode with
short circuit transfer processes.
115VAC Receptacle not working.
1. OUTPUT CONTROL switch in
wrong position. Place switch in
REMOTE.
2. Faulty OUTPUT CONTROL
switch.
3. Faulty remote control potentiome-
ter.
4. Leads or connections open in
control circuit.
5. Faulty Control PC Board.
1. Defective start circuit.
2. Poor work connection.
3. Improper procedures.
4. Defective Control PC Board.
1. Start circuit energized at all times
(read switch CR3 not closing).
2. Defective Start PC Board.
3. Defective Control PC Board.
4. Capacitor(s) in output circuit
failed. A failure is indicated if the
small vent plug on top of a capac-
itor is raised or blown out.
1. Defective R1, L1, S4C, S4D actu-
ator or S5.
1. Circuit Breaker Tripped.
2. Defective Circuit Breaker.
3. Broken Connection in Wiring.
If all recommended possible areas of
misadjustment have been checked
and the problem persists, Contact
your local Authorized Field
Service Facility.
DC-400