Talea Giro Plus SUP0320R Wassertank

Hello, I have a Talea Giro Plus here. When I switch it on, it only shows the red alarm LED. After removing the water tank, the LED next to it lights up green and goes out when the filled tank is reinserted. The test mode runs without errors.
My assumption is that the water level is not being detected. However, I cannot locate a float magnet for the sensor. How does the machine detect the water level?
I would be grateful for any tips

The first question is: does the alarm led light up or does it flash quickly or slowly?

The water level is detected by a capacitive sensor inside the machine.

The magnet on the grounds container may also be so rusty that the machine does not recognize whether the grounds container is inserted.

Good evening,
the LED is lit, not flashing.
It's not about the grounds container, but about the water tank.
I'm interested in where the magnet for the sensor is inside the machine.
From other machines I know the magnets that rise or fall in the water tank with a float according to the water level. I can't find anything like that here.

Excerpt from the operating instructions:
permanently on (one or more events): indicates: Lack of
coffee, the water tank is empty, the remaining water tank must be emptied.

There is no magnet in the water tank!

The sensor is located on the inside of the machine, unfortunately not visible from the outside.

Search the Internet for 'Talea test mode'. The individual components can be tested in test mode.

You will also find what you are looking for at https://saeco-support-forum.de/!

https://saeco-support-forum.de/threads/service-manual-fuer-odea-und-talea-serie-inkl-test-diagnosemodi-und-explo.56338/

Sorry for the long response time. Unfortunately, I'm not able to take care of the machine at the moment.
I'll continue as soon as I have a bit more peace and quiet.
Thanks for the tips and the link.