Kind of a long shot, but this happened afew weeks ago and I lost all of my files. Thought it was a software issue I could fix, but apparently LG producedfaultymotherboards and all phones manufactured before October willboot loop at some point.LG has recentlyaddressed the issue and has extended the warranty to 15 months for affected devices.
Just letting anyone know if you have a G4 that was made before October, you should backup all of you data and sell it or expect a boot loop.