Screen gets bright then blacks out

Hello Jerry2106,

It sounds as though your iPhone displays is getting brighter unexpectedly. To confirm, are you noticing this happen in different lighting conditions? If so, it's possible that auto-brightness is enabled. This setting can be enabled and disabled by following the steps listed below. You can also find these steps outlined in the "About brightness levels" section of the following article.

1. Go in to Settings.
2. Tap Accessibility.
3. Tap Display & Text Size.
4. Tap the green toggle next to Auto-Brightness to disable.

Adjust the brightness and color temperature on your iPhone, iPad, or iPod touch

You can also recalibrate Auto-Brightness by toggling that setting off and back on which can also help with resolving this issue. If you continue to have issues after these steps, you'll want to proceed with restarting your iPhone. You can find those steps listed below and in the following article. While restarting is a simple step, it can be very beneficial for resolving this issue.

1. "Press and hold either volume button and the side button until the power-off slider appears.
2. Drag the slider, then wait 30 seconds for your device to turn off. If your device is frozen or unresponsive, force restart your device.
3. To turn your device back on, press and hold the side button (on the right side of your iPhone) until you see the Apple logo."

Restart your iPhone

Have a great day!