Extruder Motor Not working during Printing
If the extruder extrudes fine from the control panel, chances are there's a configuration problem somewhere. For example, check your extruder steps/mm in the firmware to make sure it's not a nonsensical value; check the slicer settings to make sure that the filament diameter, line width, and layer height are all correct; make sure you're not trying to extrude in volumetric mode without having configured volumetric printing in your firmware and slicer correctly; and finally check your temperature control settings. When I first set up my fleabay 3d printer, I couldn't get my printer to work because the hotend minimum shutoff temp (thermistor disconnect protection basically) was set to something like 195C and the print temperature was 180C. I had an almost identical issue when I changed my fan assembly and it started blowing on the wrong part of the hotend, causing the firmware to register that entirely too much energy was being put into the extruder. Check the minimum temps for both hotend and heated bed and see if one of them is tripping your failsafes and stopping the extruder before printing even begins.