I just setup my new Taz 4 about a week ago and was having trouble with long (over ~45min) PLA prints failing. After doing some research I added a second fan to help cool the nozzle which allowed me make several prints spanning 3+ hours.
I noticed immediately that if I ran the fan at 100% the nozzle wouldn’t maintain temperature over about 165C. Running the fan between 10-25% kept the nozzle cool and it was still able to maintain 190c with no problems, but I fear it was pulling a lot of amps to do so because it fried the resistor.
Has anyone run into this sort of thing? Does it sound like the probable cause for the failure?