Bought a Prusa kit in the form of the Tronxy P802M and found that I am not able to heat my Hot-End to more than 239°C.
The temperature will climb steadily up to 239°C and then suddenly jump to 252°C on the LCD, this causing the board to switch off the heater cartridge and the temperature falling to 233°C or 235°C where it will start to heat up again to 239°C. Repeating the process.
I have replaced the thermistor in the heater block and the heater cartridge while I was at it, but that did not resolve the issue:
This is what happens on any target temperature above 240°C:
@Ryan_Carlyle I am very new to this and from what I understand is that I am not able to download the firmware from the board. I have asked the seller to send me a link to the firmware that ships with the printer so I can annalyse and re-upload should it needs tweaking. I am careful in starting with the “plain” Marlin firmware as this printer has auto bed leveling as well. Not sure if there is a way to roll back should I get stuck with the new firmware? To what firmware does the “Restore to defaults” option on the LCD revert to?
@Jeff_Dewe I did not think that this could be a PSU issue. If I heat the hotend with a heat-gun and only leave the printer to read the temperature it does the same. Goes straight to 252 from 239. Not reading anything in between.