sp135 T feed issue.

[rasorbackqq]

Used my welder last week and today the wire feed doesn't work. . Seems like there is no power to the bottom roller. I checked the trigger with a Ohm meter and both wires and the trigger are good. Anyone know how its gets power ??

 

[eddie49]

Hello and welcome to the Forum!
That would be a Lincoln Electric SP-135T. There is a circuit diagram on Page 31 here:

LINCOLN ELECTRIC SP-135T OPERATOR'S MANUAL Pdf Download

View and Download Lincoln Electric SP-135T operator's manual online. Lincoln Electric Welder User Manual. SP-135T welding system pdf manual download.

www.manualslib.com

It shows that the gun trigger switch is in series with a thermal overheat cutout mounted on the transformer, so that should be checked for continuity.
The machine is unique in that the control board ( PCB ) seems to get it's operating power from a 24 volt "auxiliary winding" on the fan ( rather than from a transformer ), so I would suggest checking that voltage.

 

[500e]

That's a different idea, if fan stops no control board voltage or machine overheats thermal trip cuts off welder, got it both ways quite a simple idea