I powered down my Nexus S 4G, and plugged in the charger. When I turned it on later, it will only go to the Google Screen. It appears toast. It worked perfect before hand. I have tried recovery and wiping cache etc, no changes. Does anyone have recent instructions for using other tools to reload the OS on this thing? I think I was on 4.1.3 OS. Sprint said they could replace it for me for $50, but thought I would spent a bit finding out if I could recover it.