Uninstall the entire oven and remove the screws coming in from the top panel. Remove the top panel and then you'll see the relay board and you can replace it. 
Category: Appliance. Share this conversation. Expert: Tyler Z. replied 6 years ago. the relay board in the back supplies the voltage to the LCD board in the front--- if you've replaced the board twice either you have a loose connection or your display board is shorted. Place the back of the electronic oven control over the board and tighten the screws to reassemble the electronic oven control. Place the electronic oven control back into its position on the oven and secure its screws. Plug the oven’s power cord into the wall outlet or turn on the main breaker. I'll be helping you with your problem today. To replace the relay bord you have to uninstall the entire oven and remove the screws coming in from the top panel. Remove the top panel and then you'll see the relay board and you ca replace it. There is no way to jsut replace the relay control board from the front. Turn off the main breaker in your home’s breaker box, open the oven door and remove screws beneath the electronic oven control at the front of the inside of the oven using a screwdriver if you have a wall oven. How do I replace a L43 relay board on a Dacor double wall oven model # XXXXX. 1. Unplug the range’s power cord, and pull the oven away from the wall if it's a freestanding oven. Remove the screws securing the metal panel on the back of the oven near the top to access the electronic control board.
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HOW TO INSTALL RELAY BOARD ON WALL OVEN