Northeast Florida averages somewhere around 68 thunderstorm days a year. That is a lot of switching, a lot of voltage transients on the grid, and a lot of opportunities for a control board to take a hit it was not designed for.
People expect board failure to be dramatic — a strike, a bang, a dead kitchen. Occasionally it is. Far more often it is cumulative, and the appliance dies weeks after the storm that damaged it.
How a board actually fails here
Repeated transients. Every surge event that a board survives still stresses its power supply components. Protection devices inside the appliance degrade each time they clamp. After enough events something lets go, usually the low voltage supply section, and it does so during an ordinary Tuesday dinner rather than during a storm.
Brownouts and dropouts. A voltage sag is harder on some electronics than an over-voltage spike, because switching supplies draw more current to hold their output. Utility work, a nearby fault clearing, and generator changeovers all do this.
Salt film across the board and its connectors. This is the coastal contribution. A conductive film across an edge connector or a relay terminal creates leakage paths that the design never anticipated. It produces behaviour that looks like a logic fault: phantom key presses, a fan that will not stop, a zone that reports something odd, a hood stuck on one speed. We check every connector shell for corrosion before condemning a board, because a cleaned and re-terminated connection is a far better outcome than a replacement that will fail again for the same reason.
Heat. Electronics live longer cool. A board in an appliance installed in an opening tighter than its specification runs hot for its whole life and reaches its failure point years early. In older beach cottages with retrofitted built-ins this is routine, and it is why a replaced board sometimes fails a second time.
What protection is worth having
Whole-house surge protection at the panel is the one that does the most for built-in appliances, because a hardwired wall oven, cooktop or hood cannot be plugged into a strip. It clamps the large events arriving on the service conductors. It is an electrician’s job, not ours, and we will say so.
Point-of-use protection for anything that does plug in — a microwave drawer, a plug-connected hood blower control — catches what gets past the panel device. Use a unit with a real joule rating and a status indicator, and replace it after a serious event.
Neither one stops a direct strike. Anyone who tells you otherwise is selling. What they do is turn a large class of common, survivable events into non-events.
What to do after a storm that hit close
Before assuming the worst, check the breaker and, on 240-volt appliances, check that both legs are present. A single open leg leaves the display lit and the fan turning while nothing heats — it looks exactly like a dead appliance and it is a dead circuit.
If an appliance is behaving erratically rather than not at all, note what it does and when. Intermittent behaviour after an electrical event is diagnostic information, and it saves time on the visit.
When you call
Tell us that the house had a power event. It changes what we bring, and it changes the order in which we test. A board that failed after a surge often shows physical evidence, and finding that evidence tells us whether the board is the whole story or whether something upstream took it out and will do it again.