i want to keep this short and say i know how you feel. I have a expobar minore iv. Before this a few machines back i had a kitchenaide. I left the button pressed in and on for brewing coffee which pretty much dried the machine out and all i was left with was a bad smell, a machine that turns on and a clicking sound. That sound i traced back to only being the pump for my machine. Did i hear right it turns on but the machine doesnt prime?
It may be just your pump, but please dont quote me. leaving the blind filter in could mean im way out of the ball park. But i hope for your sake its just a pump. Cause what you have explaned is what i had after i found it like it was.
good luck, i know what you are feeling..