@DDUJ It could be a firmware issue but more likely the MOSFET has failed, you would require a volt meter to check the controller outputs. If the D11 output on the Nano is working and the MOSFET is not switching then you need to replace the MOSFET or get a new controller.

@Hiram-be What version does it show in device manager? It needs to be version 2011 that is provided in T2Laser, then it should work unless you have some other USB issue. Make sure you reboot after install.

@Hiram-be If you are using T2Laser you can click Help / Install CH340 but if a different driver is already installed Windows may refuse to replace it automatically, in that case you must go to device manager and manually replace the driver with the one provided. If you are using other software you should contact their support for help.

@Hiram-be If you are connected to the Nano and it does not appear as a COM port then either the driver is incorrectly loaded or the device is faulty.

@donovanpl123 Set it to Uno, or your boot loader is corrupt.

@donovanpl123 It switches from USB power to external power. It should not be changed.

@Nam-Luc-Tran Your belts are loose and the axis has backlash. Servo value should be 55 or less to prevent over travel of the servo and damage to the gears.

@amacin T2Laser will output the size shown, you can check the information overlay or the G-code simulation "view" to see the size it should output. If it is not correct the problem is your controller and you need to calibrate the firmware parameters, there's a feature in T2Laser to do that automatically.

Test a shape from the Help / Samples menu to see if the problem is operator error or the machine.

@DPE The motor output is switched by the MOSFET, it sounds like you overloaded it and caused the MOSFET to short.

@bambam You can use the free T2Laser trial to test your machine, it comes with everything you need (including device driver and latest firmware).