This the second time this has happened to me, and it always happens when the service reminders start. There is no rhyme or reason to why it goes dark, except that when it does happen, it's always when I start the car. If I push any of the buttons surrounding the display, it comes back on. Has anyone else had this issue? I mentioned it to the service guy the last time I took it for an oil change, but of course it didn't happen while they had it.
I had a problem somewhat like your issue in my 2010. I had been having some 12V battery problems and I figured that it happened each time that I used an external 12V source to start the car. Everything would be OK next time I started the car (without the need for external 12V), but it would return when I had to use an external 12V source again.
this was so common in Gen 2, there was a huge recall. Let them change it out, if it's still under warranty. It takes less than a ½hr at the service center to swap one out. .
As I understand it the MFD is the screen above the dash, but it has no buttons around it, do you mean the Nav screen ? There is a setting to turn this off in the Nav menus, SETUP-DISPLAY-SCREEN OFF, maybe it's turned off, it does come back on if you press a button after being turned off and it does default to being off when you turn the car on once you've turned it off. When you first turn the car on, press setup then display and if the menu item says "screen off" then do not press it, just go back to the nav or media screen and it should then default to being on next time you turn the car on.