Hi Autowasherfreak,One question I guess when you were attempting to repair your Sunbeam mixer did you just pop the dial off the mixer with a screwdriver without removing the center screw first below the handle cap at the end of the dial?You see there is two clips attached to the handle cap that go through the cooling vent holes at the end of the dial.For future reference,to remove this cap you'll need a very small screwdriver ( like you would use to repair glasses with,I found works best ) gently lift up on the handle cap on one side & work the screwdriver around the handle cap it should of come off easily.To reveal the center screw that holds the whole dial assembly to the shaft or stem of the control.But anyways that does not matter right now it sound's like the speed control is broken besides being defective?The reason why your mixer was working only on low speed is because your mixer is "An American Classic series" correct?The speed control on your mixer is electronic,not governor controlled like earlier models.You more likely will have to find an identical mixer head for donor parts or unless Sunbeam might have the electronic control in stock for you,that has to be replaced along with the mix-finder dial since that you have some spare parts leftover?I really doubt it though for parts for your mixmaster it is from the original Sunbeam company (late 1980's to early 90's) not the one that is around now (not sure who owns it now)?E-mail me the model number I can do some looking around for you if you like?I know myself a few years ago I was repairing the Canadian version of your mixer I was told by the Sunbeam parts company in Canada that the electronic control assembly is no longer available then,this was in early 2000.Also that the original Sunbeam company was sold in 1993 I think it was about that time that I can remember the parts guy said.I wish I could be of more help?Thanks Dave