Before checking the wiring, turn off the printer and disconnect the power supply to ensure safe operation.
Use an S2.5 Allen wrench to unscrew the two screws holding the base plate. Remove the cooling fan cable and remove the bottom plate.
(1) Gently tug on the heated bed cable to inspect whether it's loose or detached.
(2) If the cable is loose or detached, use a Phillips screwdriver to loosen the screws that secure the heated bed cable, then reattach and tighten the heated bed cable.
First, heat the heated bed to 50 degrees. During the heating process, if the mainboard blue indicator light is on, it indicates that the heated bed is heating up normally. If it is flashing, it means the heated bed heating is complete. If it is not on, it indicates an abnormality in the heated bed heating, and voltage measurement is required.