A control lock or restricted interface state may be active. Check the displayed symbols and the exact instructions before assuming the buttons or electronic board have failed.
What the observation tells you
Repeated random button combinations can change other settings or enter an unfamiliar mode. A confirmation sound may mean a touch was detected while the requested action remains blocked. This differs from a physically damaged button that does not respond at all.
A useful next step
Use only the documented unlocking process for the model. If the panel remains unresponsive, record the symbol and current cooling condition. Do not remove the panel or search for hidden service-menu procedures.
Manuals and supporting guidance
Model-specific instructions take priority. These references support the practical principles discussed here; they do not diagnose your appliance.