3D printer parts DIY motherboard kit mega2560 + LCD circuit control board
The diode D1 supplied by the ramps to the mega board is not welded, that is to say, the mega2560
board needs to be separately powered by usb5v or through the power connector (it is not recommended
to power more than 12V officially). Please understand. If you want to use LCD offline printing, you need to
power the ramps 1.4 yourself, otherwise you can't use it.