No announcement yet.

Cannot Adjust the output of my TB 251..

  • Filter
  • Time
  • Show
Clear All
new posts

  • Cannot Adjust the output of my TB 251..

    I'm using my TB 251, 1999' model, with HF box on a big aluminum job. My TB amps outout is max or near, with no adjustment. The adjustment dial has no effect on the max output. The machine is welding fine on max output but cannot be turned down. The generator 120v works....everything works but I cannot turn down the amp output.......Any advice??
    Miller TrailBlazer 251NT
    Miller HF-250-1
    Miller Maxstar 150slt
    Miller ft peddles and thumb wheels
    Miller MM 212
    Lincoln power mig180c (two of)
    MM 252
    Miller Elite Dig
    Miller Pro-Hobby

  • #2
    Check position of Remote Amperage/Voltage switch S3.
    Check resistance and connections of A/V control R1; R1 is 0 to 1000 ohm
    Check hall device HD1, and replace if necessary.
    Check Field Current Control Board PC2 and connections, and replace if necessary (see Section 8-6 or
    8-8). LED2 and LED3 on PC2 light when PC2 is energized.


    • #3
      Can you adjust it if it is in regular stick mode with no 14 pin connected?


      • #4
        If you still can't figure it out, I kinda need the machines serial #