Thermal Arc PRO-WAVE 300 TSW, Service Manual

Page: 67 / 110

PRO-WAVE 300TSW
August 10, 2005 7-5
G. Defective Cooling Fan
driver circuit
components on
PCB2 (WK-4983).
G. After Power Source is turned on for approx 8
seconds check CN12 between Pins 1 and 2(-ve)
on PCB2 (WK-4983) for 24VDC supply to
Cooling fan. (Note that after approx 30 seconds
due to cooling fan on demand circuit, the
voltage will be dropped to 15VDC.) If 24VDC is
not present replace PCB2 (WK-4983) or refer to
Replacing Cooling Fan Driver circuit
components on PCB2 (WK-4983).
2. No Welding
Output and the
Cooling Fan is
rotating. A. Check the Machine is
switched into the
correct mode.
A. Check the Machine is either in Stick mode or
trigger switch is closed in Lift Tig or HF Tig
mode.
B. Ribbon Cable
connection between
PCB2 (WK-4983) and
PCB5 (WK-4919).
B. Check Ribbon Cable connections at connector
CN17 on PCB2 (WK-4983) and connector
CN2 on PCB5 (WK-4919) are firmly connected.
C. Poor IGBT Q1, Q2
Gate Driver
Connections between
PCB4 (WK-4984) and
PCB7 (WK-5012)
and/or between PCB4
(WK-4984) and PCB8
(WK-5012).
C. Check wiring and connections for Q1 Gate
Driver signal between connector CN5 on PCB4
(WK-4984) and connector CN1 on PCB7 (WK-
5012 mounted on IGBT) are connected
firmly. Check wiring and connections for Q2
Gate Driver signal between connector CN4 on
PCB4 (WK-4984) and connector CN1 on PCB8
(WK-5012 mounted on IGBT) are connected
firmly.
D. Poor IGBT Q1, Q2
Gate Driver
Connections between
PCB4 (WK-4984) and
PCB2 (WK-4983).
D. Check connections between connector CN223
on PCB4 (WK-4984) and connector CN123 on
PCB2 (WK-4983) are connected firmly.
E. Poor IGBT Q3, Q4
Gate Driver
Connections between
PCB12 (WK-3367)
and PCB11 (WK-
4963) and between
PCB13 (WK-3367)
and PCB11 (WK-
4963).
E. Check wiring and connections for Q3 Gate
Driver signal between connector CN1 on PCB12
(WK-3367 mounted on IGBT) and connector
CN4 on PCB11 (WK-4963) are connected
firmly. Check wiring and connections for Q4
Gate Driver signal between connector CN1 on
PCB13 (WK-3367 mounted on IGBT) and
connector CN4 on PCB11 (WK-4963) are
connected firmly.
Problem Possible Cause Remedy