Siemens TE803509DE - EQ.8 Series 300 - No water

Manufacturer: Siemens | Type / Model: TE803509DE - EQ.8 Series 300 | Approx. year of manufacture: 2014

Good morning,

I am now quite desperate and hope you can help me.

I have the above coffee machine (TE803509DE/08) which in the recent past no longer output coffee. The powder came partly dry in the drip tray. After descaling and cleaning it went well again for a while. A few days ago, however, nothing worked at all. Also the pump test in the SDS menu brought no water. I opened the device and checked the flowmeter for flow (blown through..) - seems to be ok. Thereupon I have ordered on suspicion a new pump incl. pulsation damper and installed - unfortunately without success.

- the machine gives no water out, neither with switching on (rinsing), with the pump test, nor with hot water
- it appears however no message like "Please water tank check" or the like
- I have it also times without the rear housing flap tested: You can't see any water flow at all and the pump is incredibly loud
- Unlike the video instructions, my machine (/08) also has a pulsation damper below the pump - this was also included with the replacement pump. I have also replaced the pulsation damper with.

Do you have any idea what I can still check or do?

Another understanding question: Why does the pump have two outputs at the top? Since there is probably no valve in the pump, the pump always pumps into both "circuits"?

I wish you a nice day,
Jonny