250ex high frequency staying on

[Rambozo]

The micro switch is stuck or needs adjustment on the pedal...most likely cause.

i turned machine off and unhooked pedal and turned machine back on and high frequency is still on.

Sounds like he is saying it does it with the pedal unplugged.

[performance]

Yep. Missed that. Shaking the cobwebs out this morning. In that case it's internal, but it could be simple as a connector or something. You should call tech support at 207 though and get a walk through basic checks