Syncrowave 250 HF DC start problem

[vortech91]

I bought a used syncrowave 250 about a year ago. been working fine, but had problems getting an arc on dc. Ive yet to weld aluminum with this machine. I tried to weld a lawn mower deck the other day and couldnt get an arc. I have

Adjusted the gap on the HF start to .010" I have an older model KC251341
verified settings are correct.
High Frequency Intesity up to 80 or 90. Like this when I bought it. I tried turning it down to 40 and couldnt get an arc.

I hear the high frequency kick on when i turn the finger control for about 1 sec and then Ill hear a click and then two seconds later another click. HF goes off after the first click. The weird thing is I can't scratch start an arc either. Every 10 or so attempt at starting an arc it will work and weld fine once the arc has started.

I think im going to clean the tungsten spark gaps and move to foot controller to see if the hand control is bad.

Any ideas or experiences would be a great help.

 

[Bobhdus]

You didn't say what brand you have but Im assuming its a Miller. Whether it is or not you might do a search on the Miller Welder forums on the Miller website. Ive seen this issue there with the fixes.

 

[zkling]

I assume you have it set on HF start? Does it work on A/C with continuous HF? Is the click you are hearing the solenoid for gas shielding? Have you established that the machine can recently arc via burning a stick rod? Also I think the gap should be around 0.008" or under. I've never had to turn my HF intensity up that high. I wonder if you have a loose connection somewhere in the HF circuit. The fact that you can't scratch start is a bit worrisome. Have you checked all lead and terminal stud connections?

 

[theknurl]

input power leads are loose......

unplug it, pull the covers and look for loose stuff

 

[vortech91]

Thanks all for your great ideas, I ended up switching to the foot control and it worked without problem. I am going to try and test the potentiometer on a scope or fluke and see if something is wrong with the thumb control. If its shot im going to try and replace the pot.

 

[lametec]

I see you got it figured out, but for future reference, if you can't even scratch start it, it's not the HF causing the problem.