, this five burner electric cook top had four burners working correctly, but the right front burner was no longer heating. The touch controls in the cooktop would illuminate when contacted and the power level could be set, but there was no heat from the one burner. The customer tried to cycle the power as that was the only thing that could really be done, so a little help was needed to get this thing fixed.
Most cooktops are simple in their wiring and operation allowing for some pretty quick diagnosis. The 240vac will usually come into the unit from a junction box under the counter, and be distributed to each of the infinite switches. From there, wiring will connect each switch to the appropriate heating element to provide a complete electrical circuit. If this electrical circuit opens somewhere along the way, one or more of the elements will no longer heat, or the entire cook top may stop operating. The only way to know for sure is to open up the cooktop and take a look.
This cooktop is a bit more high tech as it uses a control board instead of individual infinite switches for temperature control, but the trade off is it's ease of diagnosing. Because the control board is at the center for controlling all the elements, the wiring is a bit more straight forward, and much easier to get to than a more traditional unit. With the power turned off, I removed the glass top being careful of the ribbon connector to the touch panel. Once the top was removed, I could easily see each element and looking at the right front, the problem was easy enough to locate. A hot spot had developed along the ribbon that eventually burned enough to open the circuit. Without a complete circuit, this element was never going to heat.
After removing the damaged element, I disconnected all four wires paying close attention to where they attached, then I turned it over to remove the mounting brackets. These brackets are basically spring metal used to align the element with the cooktop while also applying some pressure to ensure the element seals to the glass top. After connecting the wires to the new element and installing it on the mounting bracket, it was time to reattach the top to the chassis and set this cooktop back in the counter. With the power back on, I touched the glass panel to activate the element, and it quickly awoke with a bright red glow. The element cycled on and off as expected, and once the hot surface indicator turned on, I knew this cook top was again ready for use.
Just a note - Many of the infinite switches and elements found in cooktops and ranges look similar to each other but may not have the same electrical rating. It is important when looking up range parts or cooktop parts for yourself, that you use the correct part for your particular unit based on the model number found on the serial tag. Just because they look the same doesn't mean they will work the same.