iPhone backlight blinks on then goes out. What are my options?

Solution 1:

You should take your phone in. They will fix it if they can and it's cheaper for them than giving you a new.

If you try to fix it yourself they can put the blame on you, so don't touch the hardware.

Solution 2:

It may be your proximity sensor. It's what causes the backlight to turn off when you put the phone to your face and turn back on when you move away. I was told that that's one of the few things Apple Care does actually cover.

But before you take it in, do you have a bumper on your iPhone? If so, it may be covering the sensor, which, while facing the phone, is just to the left of the earpiece. If your bumper (or maybe a dirty screen protector) is covering it, that may cause the screen to stay dark.

Hope this helps!