Installed new heating block, extrusion gears but filament isn’t extruding. What’s most likely the issue.

I think I may have skipped an important step by not heating the nozzle during installation. Really hoping I don’t have to take everything apart and start over, especially the board. I also can’t seem to cold pull the filament.

Was I supposed to heat the nozzle before installing it, even though it came as one piece? Could the extruder gear tension be too tight? I was trying to manually push the filament down into the nozzle, but it felt like too much resistance.

Man, I love this machine — but wow, it can be a real pain sometimes.