Thermal Dynamics PAK Master 150XL, Service Manual

Page: 44 / 90

REPLACEMENT PROCEDURES 5-6 Manual 0-2728
G. Logic PC Board Replacement
1. Remove the Left Side Panel per section 5.04-A.
2. Carefully remove all cable connections from the
Logic PC Board noting the location of each.
3. Remove the five screws securing the Logic PC
Board to the standoffs.
4. Install the replacement Logic PC Board by revers-
ing the above procedure.
H. Gate Drive PC Board(s) Replacement
NOTE
The two Gate Drive Boards are identical and are
removed in the same manner.
1. Remove the Left Side Panel per Section 5.04-A.
2. Carefully remove all cable connections to the Gate
Drive PCB Assembly noting the location of each
per the following chart:
Connection Description of Cable
J7
Ribbon Cable from
FET/Heatsink Assembly
J8
Ribbon Cable from
FET/Heatsink Assembly
J9
Ribbon Cable from logic
Board at J4 to both Gate
Drives at J9
J10
Twisted 3-wire harness
from J11 on top Gate Drive
Board
J11
Twisted 3-wire harness
from J10 on bottom Gate
Drive Board
3. Remove the four screws securing the Gate Drive
PC Board to the four standoffs.
4. Reinstall the replacement Gate Drive PCB Assem-
bly by reversing the above procedure.
I. FET/Heatsink Assembly Replacement
NOTE
The four FET/Heatsink Assemblies are identical
and are removed in the same manner.
1. Remove the Left Side Panel per Section 5.04-A.
2. Remove the Ribbon Cable plugs 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.
3. Disconnect all the wire lug connections to the
FET/Heatsink Assembly.
Connection Description
E14 Main Transformer (Primary)
E15 Main Transformer (Primary)
E16 Main Transformer (Secondary)
E17 (-) Output
E18 (+) Output
E19 Main Transformer (Secondary)
4. Disconnect the wiring from wire lug connections
on the Capacitor PC Board at E25 (+) and E26 (-)
terminals.