The machine displays an error with key code: 2564 during preheating on the screen.
Nozzle has not reached the preset temperature.
2.1 Print head assembly heating function is abnormal.
2.2 Mainboard nozzle heating function is abnormal.
3.1 Check if the printhead adapter board wiring is loose.
3.2 Remove the silicone protective sleeve and inspect the nozzle assembly's ceramic heating ring and heating wire for any damage.
3.3 If a multimeter is available, check if the voltage at the motherboard's nozzle heating port is normal during heating.