Fixes for homing failures, motors that stay disabled, lost position, gripper and serial connection problems on the Desktop SCARA arm.

Troubleshooting

Preliminary documentation. This product is in pre-launch preview; specifications and commands may change before shipping.

Motors do not move after power-on

E-stop: send M119. If it reports estop: triggered, twist the emergency-stop button to release it and send M999 to reset.
Power: the controller LED should be solid green. Blinking red means the supply voltage is below 22 V — check the adapter connection.

`error: homing failed`

Make sure nothing blocks the arm's path to its home position (fully folded, forearm pointing left).
Send M119 and move each joint by hand: the matching endstop should change from open to TRIGGERED.
If one endstop never changes, reseat the 16-pin arm cable.

Position drifts after a crash

The shoulder and elbow have encoders and correct small errors automatically. After a real collision, send G28 to re-home. If drift keeps coming back, lower acceleration (M204 A500) and check that the payload is under 500 g.

Gripper does not close fully

M3 S100 gives maximum force; small objects may need S60 or less to avoid stalling.
If the gripper jitters, the servo is hitting its mechanical stop — loosen the two finger screws and re-centre the fingers with the gripper open.

Serial port not found

Windows: install the WCH CH343 USB-serial driver.
Linux: add your user to the dialout group and log in again.
Use a data-capable USB-C cable — the included one is.

Still stuck?

Email service@nenpower.com with your order number, the output of M115 (firmware version) and M119, and a short video if the problem is mechanical.