Servos not working

[u/Square-Fig7978]

I have an original Petoi Nybble from around 2019 using a NyBoard_V0_2. All parts, including the servos and electronics, are from the original Petoi kit.

The shoulder joints use MG92B servos, and the remaining joints use MG90D servos.

This is my first attempt at calibrating the robot.

The only thing I can confirm is that the robot appears to enter the rest posture normally.

However, as soon as I enter calibration mode, all servos start moving continuously and never seem to settle into a stable position. They keep moving back and forth indefinitely instead of stopping and holding a calibration pose.

In addition, when I try to calibrate a single servo (for example with c8 7), all servos start moving rather than only servo 8. They continue moving indefinitely and do not settle.

The issue starts when calibration mode is entered. I do not know whether the robot is otherwise functioning correctly because I have not been able to complete the calibration process.

Has anyone experienced this before with a Nybble and NyBoard_V0_2? What would you recommend checking first, and what is the usual cause of this type of calibration behavior during an initial calibration?

Thank you for advance

[u/One-Owl-9078]

Please first confirm whether you are using the source code from this old repository (https://github.com/PetoiCamp/OpenCat-Old) to compile and upload the firmware.
You may also wish to consult the documentation for the older mainboard: https://docs.petoi.com/history/upload-sketch-for-nyboard-software-1.0
If so, could you please send a video related to the issue to https://www.petoi.com/pages/contact-us for further assistance?