Edward P Port St. Lucie , FL July 30, 2018 Appliance: Magic Chef Electric Cooktop 8670RV Magic Chef Cooktop 8670Rv: Knobs were worn & unable to read markings. How to replace Knob- Swit. Replaced with new knobs 1 People found this story helpful Do-It-Yourself Rating: Repair Time Estimate: Less than 15 minutes