This is also known as a Boot loop.
A boot loop can occur when there is damage to either software or hardware on your device. When you power on a device and it fails to complete it’s booting process (start sequence) it will enter a loop continuously repeating the boot logo.
Common causes of boot loops include:
Failing battery Board damage
Software failure can occur when a software update is interrupted or fails to complete properly, and is one of the main causes of a boot loop. With iPhones a boot loop can also be caused by a damaged or failing front camera. In some cases with the iPhone 7 or 8, a boot loop can be caused by a damaged home button or even a defective lcd that does not allow the home button to function properly. If you experience this issue try a hard reset.
If this article does not resolve your issue, stop by Bulldog Mobile Repair and visit with one of our friendly technicians.