SYMPTOM

 

CHECK

The air begins to flow, the “OUTPUT ON” LED lights

1.

Check the torch consumables to be sure they

for a brief period, but no arc is established.

 

are in tight, not dirty or greasy, and in good

 

 

shape. Replace the consumables if necessary.

 

2.

Check that CR2 engages.

 

3.

Blow off the components in the upper compart-

 

 

ment with compressed air.

 

4.

Check pilot to 391 for 1.5 ohm resistance.

 

5.

Check both 3 ohm 300 watt resistors.

 

6.

Replace Control PC board.

 

 

 

The arc starts but sputters badly.

1.

Check the torch consumables to be sure they

 

 

are tight, not dirty or greasy and in good shape.

 

 

Replace if necessary.

 

2.

Check air supply for oil or a great deal of water.

 

 

If there is oil or a great deal of water, the air

 

 

must be filtered or the machine switched to

 

 

nitrogen or bottled air.

 

3.

Check air pressure. It should be set to 60 psi

 

 

(414 kPa) while air is flowing.

 

 

 

The “THERMAL” LED is lit. The “MALFUNCTION”

1.

The machine is overheated. Allow it to cool and

LED is blinking.

 

reset. The air intakes of the machine must not

 

 

be blocked, or this will become a nuisance.

 

 

Machine will cool much faster if left on with

 

 

output off.

 

 

 

The “MALFUNCTION” LED is blinking two short

1.

The torch connected to the machine is not

flashes in close succession followed by a one second off

 

connected properly or has been damaged.

period.

 

Check all connections and look for sign of

 

 

damage to the assembly.

 

2.

The connected torch is not designed for use

 

 

with this machine, see Specifications Summary

 

 

for listing of valid torches for this machine.

 

 

 

 

 

 

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Image 17
Lincoln Electric IM491-B manual Symptom Check