Melitta Caffeo Solo - Water in a drip pan

Hello.
I hope you can help me, I am helpless meanwhile....
In the morning still coffee made without problems. After that the cleaning program is started again.
At the same time suddenly no more water comes out of the outlet. all the water runs down into the drawer.
All controlled, cleaned. no result. From now on immediately without notice.
So searched on the Internet. Sounds like a drainage valve.
Ordered. Built in according to the instructions con coffemakers.de. No change.
Dismantled again. checked, driver again aligned according to instructions (had been rotated 90° during dismantling). No change.
Then checks whether water would come without brewing unit. To do this, several people press the microswitches to simulate the presence of the brewing unit. Water is coming.
As such possibly clogged brewing unit. Disassembled, cleaned, reassembled.
All seals still look good, therefore not replaced. And a sealing problem would have probably also announced itself.
Leider still no water. Coffee powder in brewing unit falls dry in marc container..
Now I'm at a loss.
Does anyone have an idea what I could still try?
Thanks ever!
Many greetings
Peter

Update:
Repaired the machine by a specialist.
Result - only the driver was knocked out.
I could have changed it myself.... But first of all we'll figure it out...
But no matter - for now another 75.- € everything works again

Many greetings
Peter

Hi,
Thank you for sharing this, I hope to be able to fix my coffee machine for 10 bucks thanks to you.
Best,
JC

Were you able to fix your Melitta? I'm having the same issue, dry coffee grinds in the bin and water directly in the pan with steam coming out the top of the machine...
I replaced the brewing unit and still no coffee..

Please advise.

Angela