Want your iPhone to blink when you get a new text message? First, make sure Airplane Mode or Do Not Disturb is not turned on. If your phone still does not light up when you receive texts then follow the steps below.
Steps
Method 1 of 2: Make your iPhone's screen turn on
Step 1. Tap the Settings from the home screen of your iPhone
Step 2. Tap "Notification Center" (or "Notifications" in the versions of iOS before iOS7) to change your settings about which apps are allowed to announce themselves
Step #3. Scroll down and tap on 'Messages'
Step 4. Slide the button next to "Allow Notifications" to the "On" position
This is at the top of the screen and turns green. This allows the app to send you notifications.
Turn on Show on Lock Screen to allow on-screen notifications when your device is locked
Method 2 of 2: Make your iPhone's LED flash blink
Step 1. Turn on 'Show in Notification Center' and 'On Lock Screen' (so it lights up green)
Step 2. Check if your screen lights up
The next time you receive a message, your screen should light up along with the notification.
Step 3. Select Settings from your home screen
Step #4. Tap on 'Accessibility'
Step 5. Scroll down and find 'LED flash on notification
' Turn this option on (so that it glows green).