Hello,
After reading the following post:
I was able to identify the issue.
I simply disconnected the battery (a 3.3V Li-Po, 1400mAh), then restarted the board—
and voilà! It booted successfully.
The problem therefore appears to be related to the battery itself. It may have deteriorated due to prolonged inactivity (it hasn’t been used since 2020), which could be the cause of the malfunction.
Shall I change the battery ?
Best regards,
Denis