I have been working on my BigBox to resolve some of the ongoing issues like the unreliable bed levering, Constant out of sink Z motors and more. During some recent temp testing it noticed the hot end will no longer hold a temp above 220C during print. It will reach a temp of 245 but soon as plastic is fed through at only 20mm/s the hot end slowly cools down until is stabilizes around 220c making the machine useless for any material other than PLA or anything printed faster than a snail pace of 20mm/s. Will a new heater cartrage help or does my Main board need replacement?
Out of curiosity, did you check the voltage on your power supply? And the adjustment of the stepper drivers? Also, did you perform any heater calibration? Are you on the default Rumba board w/ Marlin?
Basic checks on heater cartridge first, check what wattage it is (means either taking it out or disconnecting wires to read what it says on the cart, and checking resistance or both) Check here (Google or duckduckgo.com better for searching than built in search engine) for other posts on what cart available and what resistance it should be......... numerous posts in the past. Check the voltage of the cartridge too, i.e. 12v or 24 v Check what you power supply supplies to the heater 12 or 24 ? and so on, you need a meter for resistance and volts dc. You need to understand simple volts amps ohms (I'm sure you do) watts = volts * amps or watts = V squared / resistance etc. basically V/IR take away the one you want e.g. V= I R (I =current) If the catridge is good and the volts out of the PS are good then maybe physical contact with block is not good. If all the above are ok then start looking at the control circuit.
