6.3 Troubleshooting USB Connection / Firmware detection

There are few reasons that can prevent you from connecting to your OpenBuilds BlackBox.

Typically, it would result an error:

"ERROR!: No supported firmware detected - you need a controller with Grbl 1.1x on it, or there is a problem with your controller. Closing port"

The following steps outline a troubleshooting procedure, based on the most likely cause, to help you determine the cause of this problem:

6.3.1 Incorrect Wiring

Incorrectly wired accessories can short out power rails (for example V+ to GND), Inputs or Outputs that can prevent the controller from booting up.

  • It is always critical that you cross check any wiring you do against this documentation, before applying any form of power (USB or Power Supply) as incorrect wiring can cause damage
  • If you did your checks and proceeded to power on the controller / connect it to a computer and received the error above: Immediately stop and disconnect power.
  • Disconnect everything from the BlackBox, excluding the USB cable. Now proceed to attempt another connection
  • If you are now able to connect to the controller, it strongly indicates something that was plugged in, is wired incorrectly / is a malfunctioning component.

Disconnecting everything except USB, should be your first test to resolve the “No supported firmware detected” error. You can selectively reconnect devices until the issue reappears to eliminate sections of your wiring to find the root cause

IMPORTANT WARNING:Note that some wiring mistakes can cause irreversable damage! In that case removing the short circuit may not help if it has already caused damage. Do investigate it though as not resolving the cause could destroy a replacement controller.

6.3.2 Make sure you are connecting to the correct port

On your computer there may be more Serial devices (for example Bluetooth Serial ports, other serial devices that you may have connected, etc) other than the BlackBox. The easiest way to make sure which of these devices is your BlackBox, is to look at the Serial Log while you connect, and disconnect the USB cable. The Serial Log will show the connect/disconnect events that updated the list of available ports. If there are more than one port in the list, you can deduce which is the BlackBox by paying attention to which device disappears from the list when you remove the USB cable, and subsequently reappears when you connect it:

In the example above, we can see that the BlackBox would be COM3, because it comes and goes as we connect/disconnect the BlackBox USB cable. COM5 stays, so must belong to some other device.

Windows User's Note: Your COM port numbers will very likely differ: Windows assigns Port numbers to new devices in sequence.


6.3.3 Check Device Manager

Check your computer's Device manager and make sure there are no yellow question mark, exclamation indicators, etc and that the BlackBox is present under the Ports section

6.3.4 Update Drivers

Make sure you are using the latest Device Drivers:

6.3.5 Computer problems

The problem could be related to your computer

  • DO NOT use any USB Extensions, use a short, high quality USB cable only
  • Try a different computer
  • Try a different USB cable

6.3.6 Contact the OpenBuilds Partstore

If the above fails to correct the issue, contact the support team at the OpenBuilds Partstore for further assistance:

docs/blackbox-4x/faq-usb-connection-failed.txt · Last modified: 2022/08/19 17:26 (external edit)