Reachy Base Not Powering On – No Blue LED

Users Reachy Hardware
,
1

Hi everyone,

We are experiencing an issue with powering on Reachy’s base (version from July 2022).

On Friday, 6th February 2026, the robot was working normally. I launched the ROS2 hal.py file and was able to move the base using the keyboard without any problems. However, on Monday, 9th February 2026, when attempting to power it on, the system did not start and the power LED never turned blue.

We performed the following troubleshooting steps:

  • When we manually move the robot by hand, the power LED briefly turns blue, suggesting that the connection between the DC-DC converter board and the motors is intact.

  • We can read the battery voltage and current measurements on the monitor, which indicates that the battery is connected correctly to the board.

  • We tested the emergency stop switch and verified its connectivity — it appears to be functioning properly.

  • We checked both the onboard fuse and the external fuse, both are in good condition.

  • We measured the resistance between CAN ± and GND, which shows high resistance (no short).

  • We measured the resistance between CAN ± and the 26V input on the board it shows zero ohm.

Despite these checks, the base does not power on and the LED does not light up unless the robot is moved manually.

Could you please advise on how we can further diagnose and resolve this issue?

Thank you in advance for your support.

2

Hi @marah,

We apologize for the problem you are experiencing, and thank you very much for all the details you have provided!
To help us identify the problem, we would need some additional information:

  • When you press the button on the mobile base and the LED does not light up, can you still connect to the dashboard or via SSH?

  • Could you measure the battery tension ?

  • Are you able to charge the mobile base, and if so, could you try charging it for several hours?

  • When the mobile base is charging, are you able to turn it on? If so, could you try disarming the emergency stop button and check that the LEDs in the torso light up correctly?

  • Can you try jiggling the connection of the emergency stop button and the cables (see photo), and check that the button isn’t turning blue intermittently? It could be a loose connection.

Thanks a lot and have a good day,

Claire

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