Lincoln Electric IM467 SQUARE WAVE TIG 355 - Manual (Page 42)

TROUBLESHOOTING
E-3 E-3
SQUARE WAVE TIG 355
TROUBLESHOOTING GUIDE Observe Safety Guidelines
detailed throughout this manual.
TIG WELDING
SYMPTOM CAUSE AND REMEDY
Machine does not respond (no gas flow, no 1. Defective Arc Start Switch or Amptrol. Check for con-
high frequency, no open circuit voltage) when tinuity between pins D and E on cable connector when Arc
Arc Start Switch or Amptrol is pressed. Start Switch or Amptrol is pressed.
2. Defective Protection PC board. Replace.
3. Defective Control PC board. Replace.
No gas or water flow when Arc Start Switch 1. Gas supply is empty or not turned on.
is closed in TIG mode.
2. Pinched gas or water hose.
3. Gas and High Frequency fuse (F2) blown. Replace fuse.
4. Gas and High Frequency fuse (F2) is too small. Use 1.5 amp
fuse.
5. Gas and water lines or solenoids are blocked with dirt. Clean
out and use filters to prevent recurrence.
6. Power PC board is defective. Replace.
No High Frequency. 1. High Frequency switch S12 must be in either START or
CONTINUOUS position for high frequency to function.
2. Preflow control is set too long. Reduce Preflow setting. (High
Frequency does not come on until end of preflow period.)
3. Gas and High Frequency fuse (F2) blown. Replace fuse F2.
4. Gas and High Frequency fuse (F2) is too small. Use 1.5 amp
fuse.
5. Spark Gap is too large. Set to gap specified on cover plate.
6. Power PC board is defective. Replace.
Weak high frequency. 1. Spark gap is set too close. Set to 0.015 inches (0.381 mm)
gap for most applications.
2. High Frequency Intensity control set too low. Increase to suit.
3. Work and electrode cables in poor condition, allowing high
frequency to “leak” to ground. Use good quality cables,
preferably those with a high natural rubber content, as short
as possible.
4. No shielding gas. Adjust gas flow for 10 to 30 CFH (4.7 to
14.1 l/min.) for most applications. (High frequency will not
jump from the tungsten to the work without shielding gas.)
Machine shuts down (pilot light goes out 1. If open circuit voltage is greater than 80 volts before shut-
and fans stop) when Arc Start Switch or down occurs, Control PC board is defective. Replace.
Amptrol is pressed.
Cannot preset a current on Ammeter when the 1. Defective Arc Start Switch. There should be
no continuity
Arc Start Switch or Amptrol is
not pressed.
between pins D and E of cable connector when Arc Start
Switch or Amptrol is
not pressed.
2. Defective Current Control potentiometer. Replace.
3. Defective Control PC board. Replace.
4. Defective Feedthrough PC board. Replace.