About the thread we have been working on for a few days you say:
I find it very strange, that the transistor does not work or changed the pins of the base, the collector and emitter
Does that mean that you did not know which pins on the transistor were what?
Did you just find the transistor in a junk box, and don't know even what it is?
I think we need to solve the first problem before I go on to another. this thread subject is "FAN - Problem GND??"
The schematic showed a TIP120 (NPN) is that the one you were using?
What transistor were you using? Do you have more than one of them?