Thermal Arc 185 AC, Service Manual

Page: 60 / 122

10-10
May 22, 2006
ARCMASTER 185 ACDC 200 ACDC
4. “Operating Panel Failure” (LED’s do not light
properly or weld settings cannot be established.)
Cause
Occurs when there is a connection failure
among PCB6 (WK-5549), PCB10 (WK-5527)
and PCB6 or PCB10 are defective.
Verification/Remedy
a) Verify the harness connection between CN21
on PCB6 (WK-5549) and CN2 on PCB10 (WK-
5527).
• Confirm a secure connection of the harness
and the connections between CN21 on PCB6
(WK-5549) and CN2 on PCB10 (WK-5527).
• Contact the manufacture if you find any
broken connectors or a damaged wiring
harnesses.
b) Verify the connection between PCB5 (WK-
5551) and PCB6 (WK-5549).
c) Replace PCB5 (WK-5551) and PCB6 (WK-
5549).
• Refer to section 11.3.4, 11.3.6.
d) Replace PCB6 (WK-5549) and PCB10 (WK-
5527).
• Refer to section 11.3.6, 11.3.10.
5. “High Frequency Output Failure” (Unit does not
generate High Frequency.)
Cause
Occurs when the H.F. unit is defective or blown.
Verification/Remedy
CAUTION
Read and understand this entire section before
proceeding. Extreme personal harm and test
equipment damage will occur if the procedures
are not performed accurately. The unit will
generate a High Voltage component that can
cause extreme personal harm and test
equipment damage. Capacitors installed inside
the Welding Power Source are electrically
charged for a while after the Mains ON/OFF
switch or distribution panel switch has been
turned off. Before inspecting the inside of the
Welding Power Source, leave it for about 5
minutes after switching off power for
discharging the capacitors, and then remove
the top and side panels.
a) Verify the connection between High Frequency
(HF UNIT1) and Coupling Coil (CC1).
• Verify the connection between the HF UNIT1
and CC1; confirm that the quick-disconnect
terminals are inserted onto the terminals of
HF UNIT1 (TB5- TB6) correctly and completely.
• Confirm there are no short circuits, burnt or
broken wires at CC1.
• Replace CC1.
• Refer to section 11.3.20.
b) Verify the connection between High Frequency
(HF UNIT1) and the current limiting resistor
(R2).
• Verify the connection between HF UNIT1 and
the current limiting resistor (R2), confirm that
the quick-disconnect terminals are inserted
onto the terminals of HF UNIT1 (TB3- TB4)
correctly and completely.
• Confirm there are no short circuits, burnt or
broken wires between the HF UNIT1 and the
current limiting resistor (R2).
c) Verify the connection between the terminals
between AC1-AC2 (TB1-TB2).