How. To set and card as default on ZTE grand X z777

Solution
As far as I know you cannot on that Android version. However you can try looking in the "Settings" and see if there is an option for save to card. To convert the SD card to "Internal" storage would require I newer version of Android ("Marshmallow" or newer). Now if you can upgrade to that, you can use the instructions I am including below. However, if you cannot, then to free up space I would suggest moving things like photos, videos, music, etc., (not apps) to the SD card and that would free up a lot of space.

First, you need to be using a phone that is running at least Android "Marshmallow" (or newer) or be able to upgrade to it. Second, you will need the instructions I am including below. And third, you need a phone that has not...
As far as I know you cannot on that Android version. However you can try looking in the "Settings" and see if there is an option for save to card. To convert the SD card to "Internal" storage would require I newer version of Android ("Marshmallow" or newer). Now if you can upgrade to that, you can use the instructions I am including below. However, if you cannot, then to free up space I would suggest moving things like photos, videos, music, etc., (not apps) to the SD card and that would free up a lot of space.

First, you need to be using a phone that is running at least Android "Marshmallow" (or newer) or be able to upgrade to it. Second, you will need the instructions I am including below. And third, you need a phone that has not been restricted by the manufacturer from making this change. Which does happen.

NOTE: If any of the steps are missing on your phone, or they don't work for you, then you have a phone that either has an older Android version or has been restricted by the manufacturer.


How to turn the "External" SD card into "Internal" storage on "Marshmallow".

NOTE: Please be sure you start with a blank SD card. It needs to be blank because when the card is converted to "Internal" storage, it will be formatted (wiped) and encoded (making the cards data only readable by that device).

1. Go to device “Settings”, then select “Storage”.
2. Select your "SD Card", then tap the “three-dot menu“ (top-right), now select “Settings” from in there.
3. Now select “Format as internal”, and then “Erase & Format”.
4. Your SD Card will now be formatted as internal storage.
5. Reboot your phone.

NOTE: If you don't reboot the phone, many things may not work correctly, so make sure you do.


How to turn the "External" SD card into "Internal" storage on "Nougat".

IMPORTANT NOTE: Be sure you start with a blank SD card. When the card is converted to "Internal" storage, it will be formatted (wiped) and encoded (making the cards data only readable by that device), so anything on it prior would be gone.

1. Go to "Settings", and then select "Storage & USB".
2. At the bottom of the list you should see the SD card's details, including the option to format it and make it "Internal" storage.
3. Once this is done, reboot the device and you can start running things from the card.

If you don't reboot the phone, some things may not work correctly, so make sure you do the reboot.

 
Solution