Problems with the brew group drive

Hello
Have a machine Melitta Barista T with the following problem. When I press on the machine the button 2X and then coffee. Is made the first coffee,the second you aborts after the grinding process. And says fill beans. I suspect a problem on the circuit board but am not sure. Has anyone ever had the problem and could solve it?

How old is the machine?
Has the brew group ever been serviced?
Does the machine stop after grinding or does it still try to press?

Yes brew group has been reved. When exactly it breaks off I can only say tomorrow. When resetting to factory settings it worked a few days ago for a few cups.

What do you use to descale?
With DeLonghi, for example, this error message appears, among other things, when the water flow is too low.
This may have nothing to do with the grinder.

I use pure amidosulfonic acid (the main ingredient in Durgol).
10-15 grams to 1 liter of water and descale with it. You can also run the solution through several times,

I have no idea what the customer uses to decalcify. The granules for descaling I have there. Will when the machine is there times ne descaling make. And grinder check. But still it's funny that after nen reset, it works again for a short time for a few cups.

As far as I know, Melitta monitors the bean hopper with a light barrier.
Maybe it's dirty.