Northeast Florida runs about sixty-eight thunderstorm days a year. Most of them do nothing to a house. What they do collectively, over several seasons, is age every piece of electronics on the property — and in a kitchen full of built-in equipment that is now most of what is in the room.
Two different failures
A direct hit or a large surge kills a board outright. The appliance is dead, the diagnosis takes ten minutes, and the repair is a part. That is not the interesting case and it is not the common one.
The common case is a board that has taken a hundred small events. Brief outages when a line is switched. Voltage sags when something large drops off the grid nearby. Transients that never got close to the level a surge protector treats as an event. None of them destroys anything. Each one stresses the same components in the low-voltage supply on the board, and eventually the board starts behaving in ways that make no sense.
That is what intermittent means in practice:
- A panel that lights partly, then fully, then partly again.
- An oven that loses convection and has it back the next day.
- A cooktop zone that will not answer in the morning and works all evening.
- A refrigerator that forgets a setting after a storm and holds it fine afterwards.
Every one of those is a fault the appliance cannot report, because from the board’s own point of view nothing has failed.
Why we check the supply first
Fitting a new control board into a house with a supply problem is how a customer pays for the same repair twice. Before a board goes on an estimate, we want to see the voltage at the appliance, the neutral and ground, and how the circuit is shared.
The beaches make this more relevant than it would be inland for two reasons. Older beach houses have older service equipment, and coastal grounding hardware corrodes. A ground path with resistance in it does not protect a board from transients the way the design assumed, and it is invisible until you measure it.
The second reason is humidity. Control cavities behind an oven trim panel or under a cooktop get no airflow. In a house three blocks from the water, moisture sits in there, and connector pins corrode at the crimp where you cannot see them. A corroded connector produces exactly the same symptom list as a tired board and costs a fraction to fix.
So the order of investigation is supply, then connections, then board. Skipping the first two is faster and it is wrong.
What a homeowner can usefully do
Note when it happens. An appliance that misbehaves the morning after storms, or during them, is telling you something a technician cannot see on a clear Wednesday. Write the dates down.
Do not power-cycle repeatedly to make a fault go away. It usually will, briefly, and you have destroyed the only evidence.
Surge protection at the panel is worth having, and it is not a magic fix. It addresses the large events. It does nothing about the slow aging from small ones, and nothing at all about a corroded ground.
When a board really is the answer
Sometimes it is, and then it is. What we will not do is put a board on an estimate because the fault was hard to reproduce. If we cannot explain why the board failed, we have not finished the diagnosis — and on the coast the explanation is usually somewhere between the meter and the appliance rather than inside it.