Motors not working on Magni (MCB Version 5.1)

We have a Magni robot with the MCB version 5.1. We used to run the robot using teleop_keyboard over ROS perfectly till last spring. Then, the robot was not used for about 10 months. When we are running it now, the motors do not work. After looking through the troubleshooting page, we found that the 5th (STATUS) LED does not light up anymore. We are thinking this may be a MCB issue. Please suggest steps for troubleshooting. The ROS commands are going through but the wheels do not respond. We know that the controller is not even operating because the wheels don’t lock-up when the motor switch is ON. We have also checked the cables from the motor to the MCB but still the problem persists.

The batteries are charged for a long time with the combined voltage just above 24 volts. Both push-buttons are working with both lights working with the switches.

Lets try first to see if the micro controller on the MCB has in some way lots it’s firmware. This is not likely but lets just first try that first then move on from there.

manually get a copy of v40_20201209_enc.cyacd onto your raspberry Pi home folder of /home/ubuntu (This can be done easiest perhaps by putting the file on a usb thumb drive and insert the drive into one of the USB jacks on the raspberry pi. After doing that your USB drive will appear at /media/usb0 and you can copy the file right on the raspberry pi up to /home/ubuntu).

Once you get the v40 code see this page

See almost end of that page for firmware installation from a file and use the file name you have now copied, v40_20201209_enc.cyacd

If you cannot download firmware contact me using email to and in the subject line please say something like ‘ATTENTION: Mark’ and maybe Problem with MCB

If getting the file to the Magni raspberry pi by usb drive is not something you are comfortable with then that same page has other over the network upgrade process and in that case select v35 if you do it that way.

Hello, thanks for your tip. But when I am upgrading the firmware over the network, I get the following error:

Updating firmware now. Do not power off the robot. This is expected to take less than a minute.
('Encryption:', True)
Traceback (most recent call last):
  File "/opt/ros/kinetic/lib/ubiquity_motor/", line 425, in <module>
    silicon_id, silicon_rev, bootloader_version = send__enter_bootloader(ser)
  File "/opt/ros/kinetic/lib/ubiquity_motor/", line 308, in send__enter_bootloader
  File "/opt/ros/kinetic/lib/ubiquity_motor/", line 250, in send
    raise Exception("Packet did not start with valid start byte, instead: " + cstr(start_byte) + " -- header: " + cstr(header))
Exception: Packet did not start with valid start byte, instead:  <- [] -- header:  <- []

Please suggest what the problem might be. This problem was also the same with even updating using usb.

Thanks for trying this. now send email as i discussed.
Sorry for the grief,