After few seconds (it is a bit longer for the bed) you must have the Err: MINTEMP BED error message displayed on the printer.

Set targeted temperatures back to 0°C via Preheat/Cooldown or Settings/Temperature menu.

Quickly plug back the heated bed thermistor and let the hotend cool down under 50°C.

Turn the printer off after Hotend and Bed are cooled down. Turning off the printer while the Hotend is above 50°C can cause heat creep!

If this step behaves differently please verify your connection and firmware. If it continues stop using your printer and contact us or ask for help.