Machine turning it self on.

[graffian]

A few weeks ago my tig gave some crackles[HF when it switched it self on] when I was nowhere near it,
I thought my really manky footpedal wire was to blame, it's not.

Today I had some tiny bit's of stainless to weld and the tig has turned it self on and stays on, I ended up scratch start and leading the arc onto the heat sink, then killing it while the gas was aimed at the weld, all quite difficult, especially when I tried rebuilding the bit I had just melted away! When I say on that's transformer on, gas on, HF on[unless I switch HF of of course] and pulling the foot pedal plugs doesn't do anything.

It's a Transtig 200 square wave, anyone have any ideas? I will pull the top off tomorrow, hopefully it's
something simple.

 

[Paul.]

I've had my stel tig set randomly trigger itself, initially thought it was a faulty torch switch but tracked it down to metal dust on one of the circuit boards, a gentle brush with a paintbrush and a blast of compressed air and its been fine ever since.

 

[graffian]

I've had my stel tig set randomly trigger itself, initially thought it was a faulty torch switch but tracked it down to metal dust on one of the circuit boards, a gentle brush with a paintbrush and a blast of compressed air and its been fine ever since.

I eventually got round to fixing it.
It was a capacitor across the foot pedal socket, I removed thew offending item and it was cured.
I might as well replace all the suppression caps, they all look a bit dodgy.
I cleaned the welder out and there was no metal dust, but there was plenty of cobwebs and a large pile of
mouse butt nuggets. The electronics part of the enclosure is obviously a nice place to sleep
I am a bit surprised Gerald hadn't chewed some of the yummy looking blue wires.