Jura C70: Pump hums despite new spare parts

Hi,

i inherited an "old" c70 that wouldn't run.

When you wanted to draw PFLEGE or a coffee, it always sounded as if the machine was clogged (built up pressure and then nothing came).
I then looked at the water flow diagram and noticed the following:
- if I disconnected the incoming hose to the outlet valve and pressed CARE, water came without a problem.
- when I disconnected the outgoing hose to the drain valve and pressed CARE, the machine started humming again, as if there was too much resistance in the system.
I then replaced the outlet valve.
Problem still persists.
Disassembled and serviced the entire brew group.
Problem remains.

Feeling that the machine could not build enough pressure, I then bought a new pump and replaced it.
Problem remains.


Where could the problem be? Electronics? Do I need to buy a new performance print?

Somewhere is clogged. May be that is in the hose lime or something else.