Nicholas A Slatington , PA July 09, 2017 Appliance: Jenn-Air Electric Downdraft Surface Unit JED8430ADB Jenn-Air Cooktop Jed8430adb: Broken glass cooktop. How to replace Maintop Glass. My sons and myself did the repair ourselves replacing the glass cooktop with the help of YouTube . Took our time (3 hrs ) and saved a nice piece of change ???? 2 People found this story helpful Do-It-Yourself Rating: Repair Time Estimate: 2+ hours