I recently bought an S4 on eBay, and the phone activated and is working perfectly fine minus one thing: it won't update. The update downloads and starts to install, but about ten seconds into the install the "falling Android" logo appears, indicating that something went wrong. Upon reboot it tells me the software update was unsuccessful. After messaging the previous owner, he says it was rooted, but he flashed it back to stock before selling it. He suggested wiping the cache, which I tried and failed to do (it errored out on me as well). Going in to recovery mode, it's titled "Android system recovery <3e>", and going into download mode gives me this: ODIN MODE PRODUCT NAME: SCH-I545 CURRENT BINARY: Samsung Official SYSTEM STATUS: Official CSB-OEM_CONFIG_LSB: 0x30 WRITE PROTECTION: Enable So what's the problem, and how do I fix it?