On switch on my Ender 3 with firmware V1.0.7 shows a nozzle temperature of 522 degree cemtigrade and refuses to print with an error message of “Nozzle is too lowperature” while squealing.
Please tell me how i repair this.
Is the thermistor actually seated in it’s hole in the hotend? If it is, you may have a bad thermistor.
Also, it sounds like you have a very old version of firmware, and probably main board. The latest main board is 4.2.7 and the firmware for it is Marlin 2.0.6 dated June 11, 2021.
There is nothing wrong with the older 4.2.2 mainboard, I have this on my Ender 5 plus but I am running mine with a Sonic pad and Klipper. I agree about a bad/dislodged/disconnected thermistor. I keep a couple of spares in the toolbox as they break quite easily.
The problem was a loose wire on the ?thermister? Replaced head as old one was too covered in goo for me to reliably replace just the ?thermister? Problem has now gone away. Thanks to all for the help and suggestions.