Troubleshooting - ESAB fabricator 141i Service Manual

ESAB FABRICATOR 141i
A. Unit is completely inactive: No lights come on; Displays
do not come on, Fan does not operate.
1. Primary Voltage Supply problem
a) Measure for 115VAC (+/- 15%) at Primary Sup-
ply Voltage outlet/breaker.
2. Defective primary line cord/plug
a) Measure for 115VAC on the ON/OFF Switch
(SW1) between wires from the input power
cable. If voltage is low or not present repair or
replace cord/plug.
3. Defective ON/OFF Switch (SW1)
a) Measure for 115VAC at SW1 between two wires
from SW1 to Main PCB1. If voltage is low or not
present, Replace SW1
4. Defective rectifier bridge BR1 and BR2
a) Measure for 162VDC on PCB1 connector DCOUT
between Pin 3 to 1. If the voltage is less than
130V or missing, replace BR1 and BR2.
5. Defective Main PCB1
a) Replace Main PCB1
6. Defective ribbon cable / poor connection
a) Reseat or replace ribbon cable
STICK Process Problem
A. PROCESS switch will not change welding process.
1. Defective Display PCB3
a) Replace Display PCB3.
2. Defective Control PCB2
a) Replace Control PCB2.
3. Defective ribbon cable / poor connection
a) Reseat or replace ribbon cable.
B. Preset current can't be adjusted.
1. Defective Display PCB3
a) Replace Display PCB3.
2. Defective Control PCB2
a) Replace Control PCB2.
3. Defective ribbon cable / poor connection
a) Reseat or replace ribbon cable.
C. Arc force can't be adjusted.
1. Defective Display PCB3
a) Replace Display PCB3.
2. Defective Control PCB2
a) Replace Control PCB2.
3. Defective ribbon cable / poor connection
a) Reseat or replace ribbon cable.
D. Preset current can be adjusted, but when welding the
welding current is different from preset value.
1. Defective Control PCB2
a) Replace Control PCB2.
2. Defective Current sensor
a) Replace current sensor.
E. No open circuit voltage
1. Defective Main PCB1
a) Replace Main PCB1.

TROUBLESHOOTING

2. Broken wire in machine
a) Check and replace.
3. Defective Control PCB2
a) Replace Control PCB2.
F. Once the electrode touches the work piece, the fault
indicate illuminates and arc can't be established.
1. Defective Current sensor
a) Replace current sensor.
2. Poor connection between current sensor and Control
PCB2
a) Check and replace.
3. Defective Control PCB2
a) Replace Control PCB2.
G. Fan doesn't run
1. Defective fan
a) Measure the voltage between pin 1 and pin 2 of
Funs connectors. If voltage is 20-24V, replace
the fan.
2. Defective Control PCB2
a) Measure the voltage between pin 1 and pin 2
of Funs connectors. If voltage is not present,
replace Control PCB2.
H. The fault indicator illuminates and no output voltage.
The fault indicator can be indication of either over tem-
perature or over current.
1. Over temperature
a) Allow unit to remain ON with the fan running for
1 to minutes, until fault indicator turns off.
2. Defective thermal sensor
a) There is a negative temperature coefficient
(NTC) resistor sensor attached to the heat sink,
if the fault indicator is still ON after fan runs for
5-10 minutes, disconnect IGBT OT connector
from Control PCB2 and measure the resistance.
It should be about 47K at 25℃ ambient tempera-
ture, if it is less than 20K, replace it.
3. Over current
a) With SW1 OFF, disconnect the Driver connec-
tor from Control PCB2 and turn SW1 on. If fault
indicator turns off, replace Main PCB1.
b) With SW1 OFF, disconnect the Driver connec-
tor from Control PCB2 and turn SW1 on. If fault
indicator is still ON, replace Control PCB2.
MIG Process Problem
A. Trigger switch does not switch between 2T and 4T.
1. Defective Display PCB3
a) Replace Display PCB3.
2. Defective Control PCB2
a) Replace Control PCB2.
3. Defective ribbon cable / poor connection
a) Reseat or replace ribbon cable.
B. The power source does not feed wire when torch trigger
is depressed.
6-2 Manual 0-5448