Hi centrals,
Thank you for visiting Apple Support Communities. It sounds like your iPhone will not power on, except to flash a green screen. I'd love to provide a few steps for you.
If you're able to hear sounds, such as phone calls or feel any sort of response from your iPhone, you may want to attempt to restore it using the steps here: Restore your iPhone, iPad, or iPod to factory settings. This does require using iTunes on a computer, and will erase the data on your iPhone. If you have a backup, after restoring, you may be able to move your information back to your iPhone from your backup.
If your iPhone will not power on at all, or if restoring does not resolve the issue, you may need to look into service options: Get Support.
Take care!