Hey guys, I tried to unlock my SPH-L720 (Sprint's GS5) so I downgrade baseband to MDC, all good so far, then I tried to upgrade the baseband again after the unlocking process but got an error, and that's it wifi and sound are not working, phone is slow, it has a security notice that something was block, and I can't flash it to stock ROM or anything using Odin, only got errors. Please some advice here and help, thank you