Thermadyne Thermal Dynamics PAK MASTER 50XL, Service Manual

Page: 40 / 74

REPLACEMENT PROCEDURES 34 Manual 0-2587
3. Remove the Ribbon Cable plug at J6 on the FET/
Heatsink Assembly. To remove the cable, push
down on the locking tab and pull the cable plug
out of the connector.
4. Disconnect all the wire lug connections to the FET/
Heatsink Assembly.
Connection Description
E14 Main T ransformer (Primary)
E15 Main T ransformer (Primary)
E16 Main T ransformer (Secondary)
E17 (-) O utput
E18 (+) O utput
E19 Main T ransformer (Secondary)
E25 (+) F rom Input Section Assembly
E26 (-) F rom Input Section Assembly
5. Disconnect the wiring from wire lug connections
on the Capacitor PC Board at '+' and '-' terminals.
6. Remove the two screws securing the Heatsink
Mounting Bracket to the chassis.
7. Lift up on the middle where the two FET/Heatsink
Assemblies come together and remove the Mount-
ing Bracket.
8. Slide the FET/Heatsink Assembly out and up to
remove the FET/Heatsink Assembly from the unit.
9. Install the replacement FET/Heatsink Assembly
by reversing the above procedure.
NOTE
Be sure that the top groove in the FET/Heatsink
Assembly is properly seated over the cutout in the
chassis.
5.08 Rear Panel Parts Replacement
NOTE
Refer to Section 6.07 for parts list and overall de-
tail drawing.
A. Two Stage Air Line Filter Replacement
NOTE
This part is an option and may not be installed on
all units.
1. Disconnect the gas supply hose from the IN side of
the Two Stage Filter Assembly.
2. Pull the Two Stage Filter Assembly out of the
mounting bracket.
3. Disconnect the output hose from the OUT side of
the assembly.
4. Install the replacement Two Stage Filter Assembly
by reversing the above procedure.
B. Pressure Switch Replacement
1. Remove the Right Side Panel per Section 5.04-C.
2. Disconnect the two wires connected to the Pres-
sure Switch Assembly.
3. Remove the assembly from the T-fitting.
4. Install the replacement Pressure Switch Assembly
by reversing the above procedure and noting the
following:
• Apply pipe thread sealant to the fitting before
reassembling.
C. Solenoid Valve Replacement
1. Remove the Right Side Panel per Section 5.04-C.
2. Disconnect the two wires connected to the Pres-
sure Switch Assembly.
3. Disconnect the two wires connected to the Sole-
noid Valve Assembly.
4. Disconnect the gas tube connected to the bottom of
the T-fitting.
5. Remove the T-fitting and gas fitting from the Sole-
noid Valve Assembly.
6. Remove the Solenoid Valve Assembly from the
straight brass fitting.
7. Install the replacement Solenoid Valve Assembly
by reversing the above procedure.
D. Air Line Regulator Bracket Replacement
1. Disconnect the gas input hose from the input of the
Air Line Regulator Assembly.
2. Remove the nut securing the Air Line Regulator to
the mounting bracket.