Lincoln Electric SQUARE WAVE TIG 355 Service Manual page 128

F-76
POWER PC BOARD REMOVAL AND REPLACEMENT (continued)
G2081-[ ]
PROCEDURE
Before starting the following procedure, refer to the
topic "PC Board Troubleshooting Procedures"
at the beginning of this section.
1. Remove input power to the machine.
2. With the 5/16" nutdriver, remove the sheet
metal screws that hold the front control panel in
place. Carefully lower the panel.
3. Carefully remove the 6 molex type plugs con-
nected to the power PC board. See Figure
F.23.
4. With the phillips screwdriver, remove the 6
mounting screws from the power PC board.
5. Carefully remove the power PC board. Be sure
to observe static electricity cautions.
TROUBLESHOOTING AND REPAIR
FIGURE F.23 – POWER PC BOARD
SQUARE WAVE TIG 355
12 11 10 9 8 7 10 9
J4
5 4
6 5 4 3 2 1
1 2
J5
5 6
CAUTION
Be sure to follow the recommended static-free
methods for handling printed circuit boards.
Failure to do so can result in permanent damage to
the equipment.
6. Replace the old power PC board. Mount the
board with the 6 mounting screws and phillips
screwdriver.
7. Carefully install the 6 molex plugs that connect
to the power PC board.
8. Replace the front control panel and tighten the
sheet metal screws with the 5/16" nutdriver.
F-76
8 7 6 4 3
J2
J6
3 2 1
2 1
3 4
7 8
SQUARE WAVE POWER