Originally Posted by
B. Diddy It's true that installing firmware for the wrong variant can cause issues, but this doesn't seem to be the kind of problem I'd expect. Let me see if ironass, our resident Samsung guru, has any words of wisdom.
One of these days
B. Diddy will give me an easy problem!
This does indeed seem to be a poorly, sick, Note 4. To my mind, this could go one way or the other... either a corrupt firmware or a failing hardware... such as a motherboard.
Let's assume a corrupt firmware and suggest that you download the stock Samsung firmware for your model of phone,
N910F, from
here and flash it as per
B. Diddy's linked instructions in post
#2.
Booting into Download/Odin mode can be tricky for those not used to it. I suggest pulling the battery and then replacing it and then, simultaneously holding down the
POWER,
HOME (hard key on the front of the phone), and the
VOLUME DOWN buttons. If successful, the phone should boot into Download mode fairly quickly, (2 or 3 seconds), and you can then select to continue by using the
VOLUME UP button. It may take you half a dozen attempts to do this. If you cannot boot into Download mode and re-flash your firmware, then I am afraid that there is not much else that can be done and you will most likely be the victim of a hardware issue.