Hotend Problem

Hello to everyone,
over the course of the last months, I have built my own 3d printer. While running a test print I realized the filament wasn't coming out at all. I have tried moving the pot on the extruder driver because the extruder makes a humming noise when it's trying to push filament through but can't. I have unclogged the hotend about ten times by now and haven't solved anything: when the extruder tries to push the filament it doesn't come out and gets stuck inside the hotend. I'm a bit lost and don't know what to do, does anyone have any suggestions? Is it possible I have to buy a new extruder and/or hotend?
Don't hesitate to ask for more info.
Thanks in advance!

P.S. I have a Bowden setup

hi,
which hotend you have? you selected the right thermistor in the firmware... configured the Esteps correctly, and run m303 PID Tuning heat the hotend to 200C ,can you easily push filament through the hotend,

couple things to check would be can you push filament through the hotend yourself? and does the extruder stepper turn properly with no filament?

Another thing to check would also be idler tension and your wiring (i.e. that the stepper cable hasn't come partially free).