Welcome to Beoworld! A strange fault! Are there any strange indications with the lower display panel? Do you leave the unit connected to mains power when not in use? There could potentially be problems with the control processor caused by a flat backup battery on the processor board. This can be compounded if the unit is removed from mains power when not in use. The battery is replaceable if you are happy with disassembly and soldering; there is advice on the forum if required. Alternatively it could simply be loose or broken connections between boards/motors/sensors.

Evening Guy, many thanks about your answer.... I was stupid ! 15 days ago, i changed the motor and i inverter the 2 cables when solder... haha ! Now it work perfect. THX AGAIN... Good evening. Best regard.

Ah that was an easy fix!  Thanks for letting us know - one day someone else will make the same mistake and this thread will help them fix the problem!