Washer-dryer powers on but will not start any program; start button unresponsive.

Safety first: Unplug the appliance before removing the control panel.

Step-by-step checks:

• Check child lock: Refer to the user manual and hold the appropriate button combination (often for 3–5 seconds) to disable the child lock.
• Try different programs: Select another cycle and press start to rule out a single-program issue.
• Inspect start button: Remove the control fascia and check the tactile switch behind the start/pause button. If the plastic actuator is broken or the switch does not click, replace the switch or UI board.
• Check harness: Ensure the ribbon cable between UI and main PCB is firmly connected.

When to call a technician: If the UI and wiring are intact but the machine still will not start, the main PCB logic may be faulty and needs professional diagnosis.