Chosen Solution
My Xbox was working fine until my power went off and turned back on 10 days ago. So I recently bought a new power brick to fix the problem and that wasn’t the case. Every time I power my Xbox it would seem normal and shut off when it’s going to start up. Any suggestions?
You can attempt to remedy the problem by holding the power button for 10 seconds on startup. That should do a clean power up and clear any cache (temporary) files from the hard drive that might have gone bad. Let me know what happens.