Motor tries to drive brew group past top limit

ENA Micro 90 15116
I recently refurbished the brew group, but when I reassemble the machine and power it up, the brew group motor drives the big white brew group gear all the way to the top and just keeps on running - grinding on the bottom of the long gear on the outside of the brew group. All the noises and motions seem normal up to that point. I've tried several different starting positions, but they all result in the same ending. Prior to doing all this, the machine was struggling, and I'd sometimes see Error 8, but I never saw this symptom before. I suspect that I may have a bad encoder, but I'm hoping you can advise me with some other things to check first.

Brewing unit incorrectly assembled or screw forgotten

I'm 99% sure that I assembled it correctly, and the movements are very smooth and clean when moving the gear by hand. Even if there is still a problem with the brew group assembly, how would that cause the motor to run continuously? Under normal operations, what causes the motor to stop when the brew group reaches the top? Thank you.

Hello everyone,

I have an about 5 years old Ena Micro 9 machine, about 6 months ago I overhauled the brew group, after that everything was fine, 2 weeks ago I wanted to descale the Mashiene and in the middle of it the machine started to rattle. When I pull the bowl out the motor stops working but when I put it back in it keeps on turning and tries to turn the brew group further up. In another forum I read that the mounting of the motor could be damaged. I removed the motor but did not find any damage. I also need some advice what the reason could be. Is it worth to repair it or have it repaired.

Many thanks in advance