I don't have the fully integrated machine, so mine is the start button.
Hold it down, power it on, pres 3x/5x and hold on the final one.
As soon as it flashes let go.
Because of the weird standby / boot behaviour I found turning it on first, waiting till it shows the remaining cycle time, switching it of and starting the sequence then helps with success.
And I am almost certain to have heard here that the OK button on these basically acts like a start button.
So it should be the same.