Testing and replacing wires

Hi everyone,

I’ve been having multiple problems with consistent heating with my mini v1.04. I’ve replaced the original toolhead for the Aero SE 0.5 mm about 6 months ago and the Mini Rambo in the last 3 months, but the problem persists, it cannot heat consistently as it either doesn’t go past 180C or Polylyte PLA burns (smoke coming out of the extruder) at a temperature of 200C. I also replaced the heater and resistor with E3D parts last week but the problem doesn´t go away. At this point, it seems the problems might be the wires (the printer is from 2018). Anyway, I would like to know if anyone could direct or has any tips me to a guide to test the wires, as that seems to be the only thing let that could be faulty.

Thanks a lot,.