Best answer by Ken_Griffiths
I temporarily have a play 1 from someone else, I want to add this to my existing sonos system (1x playbar en2x play 1). But I can not do this for each other. The temporary play1 will continue to flash white and will not turn green. Can someone help me?
You will need to hard reset the speaker to add it to your network. Your friend will lose everything on that speaker if you do that, so check with them first to make sure you have their authority to wipe it.
Here is the hard-reset procedure:
Factory resetting a Sonos product