Melitta Caffeo CI 970 /102

Hello
,even if I start with an empty bean container, the metal tongue at the top of the BG moves up to the stop and there is no break off! how can this be? Maybe the pump has too much
power?

Who knows about the probably rare error pattern

?

Thank you very much...

This certainly has nothing to do with the pump, if anything with the micro switch for the upper brewing piston.
A more detailed description of the error would be helpful,

But I wrote: Metal tongue always goes all the way to the top, so with double triggering of the microswitch. And that even WITHOUT ground coffee! Was
that exact enough?

Always stay friendly, otherwise it might not be fun for anyone to help. The switch may be defective, even if the brewing group operates the switch, what is so difficult to understand about this?

I already checked the switch. The question is: Why does the upper piston always move in the same way, no matter if the brewing cylinder is full or empty. I find that very curious. The three compression springs are very probably okay. Otherwise it would also be a source of error.

So, mistake found after all: The previous owner had installed a pump not intended for this model. This caused a little too much pressure and the brewhead was pressed slightly too high even when the beans were low. Instead of a new pump, I tried it with a diode in the supply line to the pump, it actually worked. But you have to pay attention to the correct polarity: If the polarity is wrong, nothing works, because the pump has an integrated diode anyway and the external diode is connected in series. A universal diode "1N4007" is sufficient. A Schottki version definitely does NOT work.

So, mistake found after all: The previous owner had installed a pump not intended for this model. This caused a bit too much pressure and the brewhead was pressed slightly too high even when the beans were low. Instead of a new pump, I tried it with a diode in the supply line to the pump, it actually worked. But you have to pay attention to the correct polarity: If the polarity is wrong, nothing works, because the pump has an integrated diode anyway and the external diode is connected in series. A universal diode "1N4007" is sufficient. A Schottki version definitely does NOT work.