Why is the old machine black?

The blacklist option of 1. aging machine can be found in the setting interface. The specific search steps are as follows: First, open the phone settings page. Then click "Security Settings" and enter the 4-digit mobile phone password. If the user has not changed the password, the password is 0000.

2. If you really need a black-numbered old-age machine, you can choose a smarter old-age machine. In case of non-stop call sign, the old mobile phone can be set to mute appropriately, or the number can be temporarily transferred to the black mobile phone.

3. First find the call records and strange numbers on the mobile phone, and then click to open the blacklist. Add the strange mobile phone number to the blacklist, unlock the mobile phone to enter the main interface, select "Call" to enter the call record, find the strange number, and select the "arrow symbol" on the right. Enter the details page and select "Add to Blacklist".