Title says it all, my trusty G4 is no longer trusty it has entered the bootloop
***Make sure you attempt this as a last resort***
**And you know for sure how to take it apart safely, look for detailed tear down tutorials first before you attempt this***
It was one of the newer models, except my issue was not a boot loop instead it was freezing on the logo and not turning on till battery was reinstalled, and even then it would still fail and shut off before even booting.