Northeast Florida gets roughly 68 thunderstorm days in a typical year. Every summer we take a run of calls in the week after a bad one, and almost all of them begin the same way: “we lost power on Tuesday and it has not been right since.”
The mental model most people have is that lightning hit something and broke it. That is rarely what happened.
The outage is the harmless part
A refrigerator with no power is a well-insulated box. It sits there, warms slowly, and does nothing that could damage it. If power returned cleanly, the unit would restart, pull back down over a few hours, and that would be the end of it.
The damage happens in the transition. Restoration is not a clean switch — it is a surge as the grid re-energises, often preceded or followed by a sequence of short outages and voltage sags while the utility works through a fault. Electronics do not like being brought up on unstable voltage. Neither do motors: a compressor asked to start against a system that has not equalised, on marginal voltage, draws far more current than it was designed to and gets hot doing it.
The half-survived board
If a control board fails outright, the diagnosis is easy and the repair is bounded. The frustrating case is the one that comes back to life and then behaves in ways that make no sense.
The panel reads 38 while a thermometer in the cabinet reads 47. An alarm announces a condition that is not occurring. One sealed system restarts and the other does not, so a household ends up with a hard-frozen freezer and a warm refrigerator and concludes the refrigerator side has died. Fans run when they should be off. The ice maker works for a day and then stops. The unit resets itself in the small hours.
These faults are intermittent because damaged traces and marginal components behave differently warm than cold, and under load than at rest. Which is why the most common piece of home troubleshooting — unplug it for ten minutes, plug it back in, watch it seem fine — is not the reassurance it appears to be. It usually means the fault is thermal, and it will be back within a fortnight.
Cheaper things that look identical
Before anyone quotes you a control board, three cheaper possibilities deserve to be eliminated, because all three imitate a board fault convincingly.
A failed sensor. A thermistor reading wrong produces a wrong number on the display and a cabinet that behaves oddly, at a fraction of the cost of a control.
A connector or harness. Corrosion or a partially unseated low-voltage connector produces intermittent behaviour that comes and goes with vibration and temperature. It looks exactly like a dying board.
The supply itself. A built-in sharing a circuit with a large appliance can brown out briefly every time that appliance starts. In older Orange Park kitchens where a built-in was retrofitted into a space never wired for it, we find shared and undersized supplies regularly. Replacing a board will not touch that fault, and the new board will develop the same symptoms.
What to do next time
Two practical things.
If you have already lost a board to a storm, the conversation worth having is about how the unit is supplied — whether it is on a dedicated circuit, whether there is surge protection at the panel, and what condition the outlet behind the cabinet is in. Some of that is electrician work rather than ours, and we will say so.
And when it does happen, write down what you observed and when. Intermittent faults are diagnosed from patterns, and a note saying “warm every afternoon, fine by morning” is worth more to us than an hour of poking at a unit that has decided to behave while we are standing in front of it.