Hello,
Today my hot end started leaking filament all over so what ended up happening is that I replaced the entire heating block but kept the exact same heater and thermistor. I would have thought that the same parts would behave the same way as they previously did, but of course they decided not to. I even tried a new heater and a new thermistor, same thing happening.
Specifically what happens is that I tell my hot end to start heating up and it shoots off like a rocket until 100C where it slows down like molasses until i get a fault in my heater.
I have tried slowing down the fan on my heatsink, and no there is not a fan blowing across the hot end.
I have tried running M303 H1 S240 to PID auto tune my heater and what will happen is it gets to about 170C and slows down incredibly slow before giving me the error "Auto tune cancelled because target temperature was not reached"
Like I mentioned, I know that my parts are working parts, they have been working just great until today and I even tried new ones.

I feel like I am at the end of my rope here and I would really appreciate some guidance. I am new to 3d printing after getting an old printer that my father used to play around with so any extra guidance and direction would be very much appreciated! I just hope that the controller isnt too old to where people arent talking about it anymore!

Thank you,
Autumn