E-3
TROUBLESHOOTING
E-3
SQUARE WAVE TIG 275
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
Lincoln Authorized Field Service Facility for technical troubleshooting assistance before you proceed.
CAUTION
GENERAL MACHINE TROUBLE
PROBLEMS
(SYMPTOMS)
POSSIBLE AREAS OF
MISADJUSTMENTS(S)
RECOMMENDED
COURSE OF ACTION
The Ammeter displays “000", but the
machine has output with no control.
One of the meters is blank.
Accessories plugged into the 115
volt receptacle do not work.
(220 volt receptacle on European
model only)
Machine regularly overheats; ther-
mostat (s) open.
1. The shunt lead connections may be
open. Check the red lead (222) and
white lead (221) twisted pair all the way
from the shunt back to the Control PC
board connector (J2).
2. The Control PC Board may be faulty.
See PC Board Troubleshooting
Procedures.
1. Check for loose connections at Control
PC Board (P4) and at the Display PC
Board (20 & 21)The Display.
2. The Display PC Board may be faulty.
See PC Board Troubleshooting
Procedures.
1. Is accessory defective? Plug it into a
known "hot" receptacle to see if it works.
2. Circuit Breaker CB may be open. Before
resetting the circuit breaker, find out why
it opened. See the Auxiliary Power sec-
tion for more information.
1. Check for proper voltage at fan.
If proper voltage is present, but fan is not
rotating or is rotating slowly, replace fan
motor.
If proper voltage is not present, but fan is
not rotating or is rotating slowly, the out-
put fan circuit on the control PC Board
may be faulty.
2. Dirt and dust have clogged the cooling
channels inside the machine. Blow out
the machine with clean, dry compressed
air.
3. Are the duty cycles being exceeded?
Read the Instruction Manual thoroughly
for duty cycle information.
4. Is there adequate clearance around the
side and back of the machine, especially
near the intake and exhaust louvers? Do
not block the flow of cooling air during
operation.
Contact your Local Lincoln Authorized
Field Service Facility for technical
troubleshooting assistance.
