Why username deactivated?
i am buying an old iphone 7 . but the old password deactivated and this device not work properly. please help me
[Personal Information Edited by Moderator]
Make sure the seller of the iPhone did everything in this document --> What to do before you sell, give away, or trade in your iPhone, iPad, or iPod touch - Apple Support
If the seller did not remove their Apple ID from the device then it is possible you will not be able to use the device and need to return it for a refund.
'Activation Lock for iPhone, iPad, and iPod touch' is a security feature that's designed to prevent anyone else from using an iPhone, iPad, or iPod touch, if it's ever lost or stolen. To learn more click here --> http://support.apple.com/HT201365
For an individual to remove an activation lock absolutely requires the information for the account that applied the lock. Click on this link to learn 'How to remove Activation Lock' --> https://support.apple.com/HT201441
If you do not know the required information and you are not the original owner, get the owner of the account to remove the lock or return the device for a refund or recycle it. The device is otherwise useless to you. If the owner is unknown and has not provided contact information as a message showing in the login screen, there is no way to contact the owner unless the person who gave you the device knows them.