Hi @drago10623
There's not much information online regarding the hood.
None of the [https://shop.elica.com/en/spare-parts/spare-parts-for-kitchen-hoods/controls/|controls] shown in this link mention that they are compatible with Cube model hoods.
The best that I can find is this [https://www.manualslib.com/manual/1090770/Elica-Cube.html?page=5#manual|page] (see Fig.7M) and this [https://www.manualslib.com/manual/1090770/Elica-Cube.html?page=9#manual|page] (see Fig.19M) from the [https://www.manualslib.com/manual/1090770/Elica-Cube.html?page=1#manual|Cube Installation and user manual] that shows how to remove some panels that ''might'' allow access to the control board (or buttons).
If the control unit is faulty, check for any part or model numbers on the board and search online for ''Elica (insert part number)'' to see if it is available anywhere or contact Elica Technical Support (see ''controls'' link above - scroll to bottom of the page and click on ''Contact Us'' for details) and ask if there are any spare parts at all for your Cube model number.