MIDWEST FASTENERS CD80, Owner'S Manual

Page: 18 / 26

©2001
MIDWEST FASTENERS, INC.
—
CD 80 Stud Welder 17
TROUBLESHOOTING CHART
4. Welder powers on, but
does not operate.
5. Weld is excessively hot
regardless of voltage
setting.
6. Consistently poor or
erratic welds.
E. Shorted weld SCR.
A. Shorted charge SCR.
B. Faulty printed circuit board.
C. Open voltage potentiometer.
A. Improper gun setup.
B. Improper grounding, cable
installation or incorrect polarity.
C. Weld cables coiled.
D. Incorrect weld voltage setting.
E. Studs (or Pins) not
perpendicular to workpiece.
F. Faulty printed circuit board.
Unplug PC Board and check
continuity between SCR heat sink
and negative (–) buss bar. No reading
should be observed. Replace SCR if
continuity exists.
Check continuity across SCR. No
reading should be observed in either
direction. Replace charge SCR if
continuity exists.
Replace with new PC board if defective.
Replace defective voltage
potentiometer.
Check gun for proper setup (see page 10).
Check grounding and cable installation
for proper setup (see page 9).
Straighten out cables or place in
random loops.
Adjust as necessary (see page 13).
Adjust gun set up as necessary. Replace
bent or defective legs (see page 10).
Replace with new PC board if defective.
(continued)
PROBLEM POSSIBLE CAUSE CORRECTIVE ACTION
If you need assistance
with setup, or operation, call
MIDWEST FASTENERS
Technical Support at
(800) 852-8352
Monday through Friday
between 8am and 5pm
Eastern time.