Thermal Arc ARCMASTER 300 AC/DC, Service Manual

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300ACDC
12
MAINTENANCE
12 – 32
5) Remove the 12 screws and then detach the secondary diodes (D2, D3, D4, D5, D6, D7).

Do not have the wrong direction of the diodes when reinstalling.

Before installing a new diodes, apply a uniform coat of silicone compound (Shinetsu Silicone G-747 or
equivalent) on the base.
3.33 Secondary IGBT (Q25-Q26) and PCB18-PCB19

1) Remove the Side Panel. [Reference page : 11-1]
2) Remove the PCB16 (WK-5569). [Reference page : 12-16]
3) Remove the PCB20 (WK-5499). [Reference page : 12-17]
4) Remove the PCB17 (WK-5570). [Reference page : 12-16]
5) Remove the hall current sensor (HCT1). [Reference page : 12-29]
6) Remove the one screw and one post, remove the bus bar.
7) Remove the two connectors and four screws. Remove the two secondary IGBT (Q25, Q26).

Before installing a new IGBT, apply a uniform coat of silicone compound (Shinetsu Silicone G-747 or
equivalent) on the base.
D2
D3
D4
D5
D6
D7
2
1
1
1
2
2
3
3
CN1 CN1