I realize this is an older post but in case other people find this I wanted to post my insight on the problem. This has happened to me twice in short time I've own my Samsung TV (1yr) so it definitely seems like a common problem. This will happen even if the TV is turned off during the power surge/outage so it isn't some kind of corrupted data like others hand mentioned. Unplugging the TV and letting it sit overnight should solve the problem and let me explain why this most likely works:
Why does this work?
It seems Samsung is using some type of resetable fuse (IE: multifuse, polyfuse or polyswitch etc). Instead of burning out and needing replacement like traditional fuses, when these fuses overheat, they loose conductivity and protect the device. Once removed from power they can take hrs/days to regain their original structure, return to a low resistance state, and allow power to flow again. This is a great thing because it protects the device and you don't have to open up the case to replace fuses. However, this can be a really bad thing for consumers that have no idea what is going on and think the device is trashed.
If unplugging the TV for 24hrs doesn't fix it, then it is probably a bad power supply (Most likely a failed cap) and that would be a valid reason for repairs or replacement.
Good luck with your fix!
Note to SAMSUNG: If any Samsung reps read this, I highly recommend you put a note about this in the setup guide explaining this because this is very common (Happened to me twice in 1 year now) and a lot of people might think the TV was dead or faulty. If they end up replacing the TV, I bet they wont be buying another Samsung either.