Mary needs help

Hey guys one of my readers has a problem with her Delta Model ss350 and needs some advise. Has anyone had the problem she describes below and have a solution.

My guess is either the Variable speed switch or the Control PWB. Anyone else care to comment?

Exploded view of the machine.

From Mary:

Hi Steve,

I was wondering if you or any of your readers know anything about malfunctions of a scrollsaw. Mine recently started running at high speed even though the dial is at low. It is an intermittent problem so I can be happily scrolling along when all of a sudden, it will burst into high speed - sometimes it lasts for a second or two and sometimes it gets stuck there so I have to turn off my machine and walk away, but when I come back, it's fine (for a while anyway).

My scrollsaw is a Delta and it's about 3 years old (and out of warranty). Could it possibly be a quick fix like changing the fuse?

Any help would be appreciated.

Thank you,

Mary