Lincoln Electric PRO-CUT 60 SVM104-A Service Manual page 83

TROUBLESHOOTING & REPAIR
TRANSISTOR MODULE REMOVAL
REMOVAL/REPLACEMENT
PROCEDURE
NOTE: It is recommended that when
the Transistor Module is replaced,
the Power Board and the Control
Board should be replaced.
NOTE: See Figure F.15.
1. Disconnect input power to the
machine.
2. Remove the Left Case Side
assembly.
3. Perform
DISCHARGE PROCEDURE.
4. Perform the POWER BOARD
REMOVAL PROCEDURE.
TRANSISTOR
MODULE
FIGURE F.15-Transistor Module loca-
tion with Power Board Removed
5. Remove the two socket head
cap screws from the Transistor
Module using the 5mm Allen-
Type wrench.
the CAPACITOR
SOCKET HEAD
CAP SCREWS
(TORQUE TO
26 IN/LBS (2.9 N/M))
6. Remove the Transistor Module
from the heat sink.
7. Install the
Transistor Module.
a. Clean the heat sink surface
with "000 fine steel wool.
b. Rinse the heat sink surface
with alcohol or acetone.
c. Apply a .002" to .005" coat
of joint compound evenly to
the heat sink
surface and the Transistor
Module mounting surface.
Use Lincoln
Compound T12837,
equivalent, such as Dow
Corning #340.
d. Press the Transistor Module
onto the heat sink surface.
Remove the module to make
sure enough joint compound
has been applied.
removed, both
should have an even texture
with no bare spots.
even-textured look does not
appear, re-apply the joint
compound.
e. Mount the Transistor Module
on the heat sink with the
5mm socket
screws to 26 in/lbs. Partially
tighten each cap screw one
at a time to avoid uneven
torque on the base plate.
8. Install replacement
Board. See POWER BOARD
REMOVAL PROCEDURE.
F-42
replacement
mounting
Joint
or
When
surfaces
If this
head cap
Power
PRO-CUT 60