Can you force the device into recovery mode? You need to hold up and power simultaneously during the startup sequence. It may take a few tries to get the timing right if it is automatically rebooting and you don't get it right first try, don't give up immediately.
If you can get recovery mode launched, it will go into a menu with options such as those seen here:
(Image Credit HardReset.info)
While most of those options have nothing to do with bootlooping, wiping the cache may fix a software issue, and factory resetting will delete all your data but will almost guaranteed fix one (though, again, would delete all your data). Using the bootloader or applying update settings may also help if you can source the right files for your device.
That is all assuming it is some kind of software bug. If none of that works, it is likely a hardware issue, and there are many faulty parts that can cause bootlooping from the battery to the cameras, but the most likely is a motherboard issue which would need to either be replaced, or repaired by a dedicated board repair specialist.