Have you re-set the TV? As a D-Series 2011 model, your TV must have been set to auto-update in your on-screen menu, as this TV, has had many up-dates.
I suggest you go to the Samsung Support page for your model (and country), and download the PDF manuels, and do a full factory re-set.
Also of note; did you download the USB update from your countries (regions) Samsung site? There are different download files depending on where you are in the world, and they are not interrchangeable.
For the last few months my smart tv UN55D8000 has been turning itself on and off again. It hasn't been bad though. Once or twice here or there and it would then be fine. Last night it was so bad I contacted Samsung tech support. They told me to update the software via USB and it should fix the issue.
Everything was fine and the tv found the file on the USB, but then spent 3 hours on the black screen with white lettering saying "Samsung smart tv". After speaking with tech support several times over the course of the 3 hours I was told to unplug it from the wall. That it would fix the problem with the update. I was assured that I'd be able to turn the tv back on.
I plugged the tv back in and it turned itself on and off 30+ times in only a few minutes time worse than ever before and wouldn't go past the Samsung smart tv screen. The tech then told me I had to call for service and someone would come out eventually and since the tv isn't under warrenty any longer, it will probably cost a pretty penny. (I should have just got a new tv on Black Friday).
After getting frustrated with the whole situation and unplugging it multiple times and removing the usb drive, I've gotten the tv to a normal screen and I'm able to use the remote to go into the menu finally. It's still having issues and I can't get the update to install (I've finally gotten it to 5%, but it won't go further).
The software on the tv has never been updated before because it says "up to date" if you use the "online" option for the updates. Does anyone know how I can make it update? I've read a ton about the Samsung TVs being giant expensive paperweights, etc... Before trying to take it apart (I'd have no clue what I was doing) I'd at least like to get the software updated.