Most softeners have a control head on top of the tank, a panel with a display, a few buttons, and a cord to a wall outlet or a small transformer. When that panel goes blank or shows the wrong time, the first instinct is to open it. Before you do, decide which part of the job is yours.
Checks that are yours
Start with the outlet. Plug a lamp or a phone charger into the same outlet to confirm power is there. Look over the cord and the transformer block for a loose plug, a cracked housing, or a scorched smell. If the display is dark, check whether the unit sits on a switched outlet that someone turned off, and whether a nearby GFCI outlet has tripped. If the time is wrong after a power interruption, reset it and confirm the regeneration settings written on the install paperwork. If you cannot find that paperwork, photograph each display screen before you change anything, so you can get back to where you started.
These steps are reversible. None of them requires removing the cover, touching the valve, or working on the plumbing.
Checks that belong to the technician
Stop at the cover. Everything behind it, including the circuit board, the drive motor, and the wiring between them, is where a homeowner can turn a small fault into a shock or a wet floor. If a cycle stalls partway through, if the unit regenerates at odd hours after you have reset it, or if the display shows an error code you cannot match to the manual, the cause could be the board, the motor, or the valve position. Those repairs need someone with the manufacturer's service documents and the right tools.
Ask three questions before you open anything
Is the fault in the power path or inside the unit? Does the manual list this step as an owner task? If you guess wrong, would the house lose water or would water go where it should not? If any answer is unclear, call the company. Then ask whether a diagnosis visit is billed separately from the repair, and whether the company will show you the fault on the screen or the board before it replaces anything.
Leave a short note for whoever comes next
Whatever you tried, write it down in a few lines: the time, what you checked, and what changed. A technician who reads that note can skip the basics and go straight to the board or the motor. Keep the note with the install paperwork so it is still there when the next person arrives.