Are you also able to disable the Quick Start Menu?
If you can, then while still in the System Settings, I'd scroll over the the far right-hand side and click on the "System Update" to see if by chance there is an update needed to allow the Quick Start Menu to fully load.
But if still no luck, perhaps you might want to give a call to Nintendo's 1-800-255-3700 (6 am ~ 7 pm Pacific, everyday) Customer Service number, and one of the service representatives can do some over the phone troubleshooting to determine exactly what the problem(s) might be, and then talk you through any needed steps to correct this or set up another repair if that is what's needed, sorry.