How reset to factory default and manage Phantom 1 (Gold) with old software version?

[billybons]

Hello!

I have 2 Phantoms 1 (Gold), one of its suddenly stopps to play.

Both have old software (I don't know certainly which version, but iOS app Devialet see both of its and ask me to update.
I don't want update software because I don't understand current state of Phantom, which stops to play.

I see it and can connect via bluetooth, but no sound.
I see it when it connects to router with ethernet cable (and can ping from other computer).

But I can't do anything else with it.

Questions:
1) how can I reset to factory default?
2) is there software which works with early versions of Phantom?

Hope you are able to help!