I've got a Galaxy S5 that I purchased from someone earlier today and it worked well until I did some type of software update, it went well but then restarted and it's been messed up since. Now, whenever I boot up the phone it boots fine all the way too the Sprint Spark screen and it just hangs, and hangs and then restarts again, and goes through the same process. I've tried reflashing the device using Odin but I keep getting an error "SW REV CHECK FAIL" with some other stuff. I've tired to do so much, I tried resetting the device and the cache using the options. Please, can someone offer me some help. It's a 900P and it's a Sprint device. I just got back from a funeral a little bit ago so I'd love to get this thing working finally, I've been working on it all night.