What, no numbers printed on the screen of the balance!!! oooooooooooppps let s fix it!
What i did: re-melt the connections of that little µprocessor (a lot!!) being carefull not to make shortcuts with some Sn-Pb melted metal. in fact i had discovered that pushing it made the creen parts work again erratically, that was a bit clue!
Still a few problems... lets melt the other side of the µprocessor too
the cause of the problem : the pad pushing on the µcontroller that got misconnected due to stress. i removed a bit of plastic... problem solved.