Geeetech

You probably need the CH34* drivers. Had similar problem. Printer LCD was working, but no USB connection and unable to flash firmware. I got eventually a new board because of a bad chip. You can try the following: If you have VMWare parallels or similar software, create and boot a Ubuntu 17:10 Virtu...

Also; when you connect with USB, and for example Repetier-Host, you can simple send the Following commands: "M211 S0" => Disable Software endstops Do your calibration, after sending M211 S0, you will be able to select Move Z-Axis => 0.1mm and move negative. "M211 S1" => Enable Software endstops. Ben...

Either directly through the website or your reseller if you used one.

Had a similair problem, after providing some tests they will make you do with a volt meter, they shipped me a new board.
Now printing very happily. Currently upgrading the Hot Bed to a MK3 Black Alu, and 24v.

Hope this helps.