Gee,

I have a 210EXT also, a 2015. I'm guessing that yours is the two knob type.

I don't know if I can offer much help, as you've undoubtedly go more time on a 210 than I do.

But, if your Stick mode is functioning well, maybe your Pedal pot conked-out.

So, I'd undoubtedly try a TIG torch with the 2T torch switch, if you've got one around.

You didn't mention how much gas flow you were using.

Otherwise, I do believe the is a so-called hidden menu for the pre-2015 210EXT models, which does have a couple of settings for the HF start time and frequency. Maybe Mark can speak to that, as it seems like it's never been articulated that I can tell. But HF starts don't seem to be your problem.

I hear the standard pedal can lose its place on its gear drive, which may account for why the contact switch portion of it shows the HF current, but nothing more.

Please let us all hear how this turns out. I'll keep watching this thread, too, so that I may learn something.