Coffee maker powers on but will not start brewing when the start button is pressed.

Safety: Unplug before removing the control panel.

Steps:

• 1. Check prerequisites: Ensure water tank is full and seated, drip tray and grounds container are in place, and service door is closed.
• 2. Cancel previous cycle: Press and hold the stop/cancel button (if available) for several seconds to clear any paused cycle.
• 3. Test other buttons: If other buttons respond but the start button does not, the start key or touch sensor may be faulty.
• 4. Inspect keypad (advanced): Remove the front panel and check the tactile switch or capacitive sensor board. Test continuity of the start button and replace the UI board if defective.

Resolution: Replace the user interface board if the start input is not recognized and wiring is intact.