TROUBLESHOOTING AND FAULT FINDING
I!'\ Notes: The following operations must be performed by qualified electricians with valid
\!/ certifications. Before maintenance.please contact with us for professional suggestion.
1. ARC250/275/300/315/ 400 fault symptom and remedy
Fault symptom
Power indicator is
not lit, fan doesn't
work, no welding
output.
Fan is working and
abnormal indicator
is lit. no welding
output.
Remedy
A. Make sure power switch is close.
B. Make sure the electric wire net connecting to input cable is working alright
C.
H
eat
-
sense resistance(4 pieces) is broken.(24V relay has problem)
D. Power source board ( Bottom board has problem, no DC537V output
voltage),
a) Silicon bridge circuit is broken, cable is loosen.
b) Part of board is burnt.
c) Check cable between air switch and the power source board, power
board between MOS board.
E. Subsidiary power source on the control board has problem. (Contact with
dealer or manufacturer.)
A. Check if components are poor connects.
B. Check if connector of output terminal is break circuit and poor connect.
C. Inverter circuit may go wrong. please disconnect the power supply plug of
the main transformer on MOS board (close to insert of fan VH-07) then
res ta rt the machine.
a) If abnormal indicator is still on ,some fieldistors on MOS board are
damaged ,find out and replace them with same model
b) If abnormal indicator is off:
1) Maybe transformer of middle board is damaged, measure primary
inductance value and Q value of main transformer by inductance
bridge.
2) Primary value is parallel circuit, L=1.2-2.0mH, Q>40
If inductance value and Q value is low, replace it.
3) Maybe some of secondary rectifier tube of transformer is broken,
check and replace rectifier tube.
D. Maybe feedback circuit is in fault.
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Summary of Contents for POWER TOOLS MAG-140A
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Page 20: ...MAG MMA140 LISTA DE PE AS 19...
Page 21: ...MANUAL DEL UT LIZADOR MAG 140A 20...
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Page 40: ...MAG MMA140 LISTA DE PIEZAS 39...
Page 41: ...OWNER S MANUAL MAG 140A 40...
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Page 60: ...MAG MMA140 SPARE PARTS LIST 59...
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