Lincoln Electric SQUARE WAVE TIG 355 Service Manual page 102

F-50
CONTROL TRANSFORMER (T5) VOLTAGE TEST (continued)
FIGURE F.13 – LOCATION OF CONTROL BOARD AND CONTROL TRANSFORMER
PROCEDURE
1. Remove input power to the machine.
2. With the 5/16" nutdriver, remove the machine
case top and sides.
3. Locate plug J4 on the power board. (Do not
remove.) Also locate the two black secondary
leads. See Figure F.13.
WARNING
ELECTRIC SHOCK can kill.
• With input power ON, there
are high voltages inside the
machine. Do not reach into
the machine or touch any
internal part of the machine
while power is on.
3. Turn input power ON.
TROUBLESHOOTING AND REPAIR
SQUARE WAVE TIG 355
4. Check for 120VAC at the primary leads #265 to
#266.
A. If 120VAC is present at leads #265 to
#266, go to Step 7.
NOTE: If input voltage varies, the control
transformer voltages will vary
accordingly.
B. If a very low or zero voltage is shown at
leads #265 to #266, go to Step 5.
5. Remove input power to machine.
F-50