I work on these things every day for a living and I can tell you with 100% certainty that to resolve the issue you have to replace the control panel/user interface. Replacing the main PCB does nothing. According to LG this is caused from moisture getting in the control panel. I’m not sure if I buy that due to the fact that the electronic board(s) under the buttons are all covered with a 1/8” thick clear rubber coating to prevent moisture from getting to the panel. I normally just order the control panel assembly. It’s much easier to change than trying to change out the little boards underneath the user interface. It’s also cheaper. On this model, LDF5545ST, the part number from the dishwasher control panel assembly is: AGL 75172601. Basically you take the bolts out of the top part of the door and the panel assembly will come right out. Make sure the power is off when you do. Most of them there is only one plug.