Why can my washer-dryer no longer be switched on (display or the LEDs remain dark)?
If your washer-dryer won't switch on at all, it is obvious to check the power supply first.
Is the plug plugged in? Is the socket supplied with power?
To test the outlet, plug in another appliance and see if it turns on.
If it does not, a circuit breaker may have tripped. If the outlet works, disconnect the unit from power for 20 minutes, then try again. If the washer-dryer still does not work, a service technician will need to check it.