CISCO SPA 303 firmware upgrade loop

[ksanch]

Hello,

I have a problem with a Cisco SPA 303. It keeps rebooting in a firmware upgrade loop. The phone comes up, the 3cx logo, extension info etc are ok, then 4-5 second after, the phone reboot displaying:

Upgrading firmware
Please do not unplug power
Phone will reboot automatically​

- I already tried to delete this provisonned phone in the extension and to provision it again doing a factory reset. Still the same.
- If I don't provision it, the phone does not reboot in loop.

Any support ?
Thanks you.