No announcement yet.

2002 Syncrowave 180SD Troubles

  • Filter
  • Time
  • Show
Clear All
new posts

  • 2002 Syncrowave 180SD Troubles

    Hoping I could get some help in troubleshooting my early 2002 LC (non digital) 180SD. I bought the unit new and have only used it for carbon steel sheet metal work & its been awesome. A while back, I tried to weld some light 18ga aluminum and the only way it would weld was in DC, E+. Being a novice with aluminum, I finished the repair in that mode.

    While it sounds pathetic, I was unaware until recently that this machine has an issue & will not weld in A/C & certainly should. What happens is it will arc fine, but has no amperage adjustment. Its basically stuck at what I would guess is about 10 amps. I can set the dial anywhere from 10-180A, & fully depress the pedal & still just an entry level 10A arc. I did reset the points to spec. However I found they were only slightly off. Zero improvement.

    It will weld Ferrous metals in DC mode E+, or E-, no issues at all & full power. It's only in A/C where the output is low & non adjustable.

    Following the schematic it looks like when in A/C the "work" connector is direct to the Transformer & the Electrode side loops through the SCR's differently, so I am guessing its either the SCR's or something with the control Board?

    I tested voltage the open circuit volts with the process switch flipped to Stick & I have 30.8 vdc & 40vac in all three modes (+,-,a/c) Not sure what it should actually be.

    Thanks for any advise you can give.
    Last edited by 68ragtop; 06-12-2019, 11:18 AM.

  • #2
    Here's a the current flow in DC +E & in A/C mode Does anyone know if the way the SCR's acre controlled by the main board is different when its in A/C mode VS DC? There is a circuit that closes in A/C mode (pink) that must change something in the main board, but I have no idea if its how it reads the load on the hall sensor, or the way it controls the SCR's? Maybe both?

    What puzzling is it welds perfect in DC modes, its only in A/C mode that I have no amperage. Just a steady arc that I could maybe weld a soda can & nothing thicker.

    Could it be a bad SCR, Hall, or something else? Or does the fact that it will weld normal in DC point to the control board. I was going to open the loop on 37/39 in ac mode & see what it does, but I am not sure what that would do. My thinking is it would make the board think its in DC mode & maybe it would weld in A/C? Not as a fix, but as a way to trouble shoot?