On 22 Jul 2022, at 13:46, James Beckett <jmb.groups.io@...> wrote:

?Could this be another "failed firmware flash" case (initially by the previous owner)? Other posters here have advised that the flashing process can be very sensitive to both the Serial-TTL interface and the xmodem software used, flashing often produces no error but has failed in some opaque way and continues not to boot.