Thermal Arc 300GTSW Pro-Wave, Service Manual

Page: 62 / 130

pro-wave 300gtsw
6-24
June 21, 2012
6.24 PCA Input Diode Bridge (D1) Test
Procedure
Refer to figure 6-21
1. Select the Ohms scale on the digital meter.
2. Check CN14 on Main Circuit Board between pins
1 and 2. The resistance should read 44 Ohms.
3. Select the diode test setting on the digital meter.
4. Check the diodes between the following:
MAIN CIRCUIT BREAKER (MCB) wire R, and TB6
on the Main Circuit Board;
MCB wire S, and TB6 on the Main Circuit Board;
MCB wire T, and TB6 on the Main Circuit Board;
MCB wire R, and CN14 pin 4 on the Main Circuit
Board;
MCB wire S, and CN14 pin 4 on the Main Circuit
Board;
MCB wire T, and CN14 pin 4 on the Main Circuit
Board
6.25 PCA Input Diode Bridge (D1)
Replacement Procedure
Refer to figure 6-21.
to remove the Input Diode Bridge (D1), do the
following:
1. Remove the Main Circuit Board (PCB1) per page
6-13.
2. Remove the input power and sensing lugged wires
from the input terminals R and two RED, S and
two WHITE, RED input line and BLACK.
3. Remove screws from all terminals with lugged
wires, and the corner bus bar.
4. Remove the two screws that secure the Input
Diode Bridge to the main chassis frame.
5. Slide the Bridge out from under the bus bar.
to replace the Input Diode Bridge (D1), do the
following:
1. Spread a light coating of thermal compound on
the bottom surface of the Bridge.
2. Slide the Bridge under the bus bar.
3. Reverse the remaining removal steps above. When
replacing the screws that secure the Bridge to the
chassis, make sure both screws are started before
tightening them.