Originally Posted by jk0l
Yeah. I tried to update to Kitkat and have flashed with almost every version of odin and the results were all the same.
However, I didn't encounter problems like you did.
Only the system (rom), recovery, boot (kernel) were flashed, and the modem (radio) and bootloader weren't registered into the phone.
And since my bootloader was still the old one (Knox-free), I was able to downgrade and did OTA update.
So now, for your situation, I can only think of trying to update with Kies.
DO NOT AND NEVER try what I did since you don't have download mode to confirm whether you have the new Knox bootloader, so you might end up BRICKED.
Again. Try to update with Kies. DO NOT downgrade by odin flash old firmwares (4.2.2).
And if Kies works out for you, let the other member (who's having same problem) know.
This is the #1 thing I am seeing members doing, attempting to downgrade
from KK 4.4.2 Kitkat. It's becoming a trend so to speak. Although I will say it is sometimes a hardware error/issue, not many are reading before installing/attempting to downgrade.......
To the others.......
Once there, there is no going back. Yes you can flash Custom Roms all you want as long as you do not attempt to successfully downgrade the KitKat Knox Bootloader and pass. The OTA even tells you so and this is on any Galaxy phone you buy, not just the Mega.
If you can
get into Recovery, then recover one of your backups, only
if you didn't update to the Official KitKat 4.4 with the Updated Knox Bootloader either thru OTA or Odin
If you can
still get into download mode then you are somewhat okay and there is still some hope. You can try flashing the Official Firmware to recover. Only
flash ( pre KitKat 4.4
) Official Firmwares thru Odin if
you didn't already update to the Official KitKat 4.4 with the Updated Knox Bootloader either thru OTA or Odin.
If you can not
get into Download Mode and the phone does not boot up or plugging in the phone to the computer with no battery installed you get the qhsusb_dload mode, then the possibility that you are likely bricked is good.
From here you either send it for JTag or see if someone with the same Phone
can make you a debrick image for you to burn to a memory card so your phone can be able to boot off it into Download Mode and Odin the Official Firmware. You will need to search for this method.