Galaxy s6 keeps rebooting

A

AC Question

Hi guys,

I recently done the new android marshmallow update and ever since it starts up finishes boot you get 4 / 5 seconds and it shuts down and restarts. I've tried safe mode and also cleared cache and rebooted. Next step would be to do the factory reset but I have a lot of baby photos that haven't came across to google photos from this phone and I'm under the understanding factory reset will wipe them ? I'm mostly worried about recovering the photos as the phone is insured and can be replaced. Any help is very much appreciated.