i used DJI NAZAM Assistant_2.20
I tried to upgrade firmware to 4.02 of phamtom 1
after the upgrade failed, the phantom sound bip bip all the time
how reset ?

when I connect the phantom to the pc, it does not detect it anymore

I fixe it. I don't know how
i used software DJI NAZAM Assistant_2.40 and the update worked even though the drone was not recognized
I do not touch anything from now

Glad you were able to fix it sir

Thanks for keeping us updated. It's really nice to know you have figured it out quickly. Enjoy it!