Pump F50

Hi, my F50 keeps saying "faucet open, faucet closed" and nothing happens until at some point the pump runs and the system is filled. Then I can draw two coffees and the game starts all over again. When I draw coffee, I notice that the water flow is lower than it used to be. As a result, I have replaced the flowmeter. However, the problem has not been solved. Now I have noticed that the pump gets quite hot. There is also a smell of overheated electrical parts. As if something is stewing. Also, the machine then does not purge when turned off. The pump does not start at all when the machine displays "rinses". Does anyone have a tip? Is the pump perhaps broken? If so, should I replace the diaphragm damping element at the same time?
GreetingsJosef

Has the machine ever been thoroughly decalcified?