Did you leave the batteries in the remote when you did this? Stupid question, I know. I bought the 54" SW5451-C2 about a month ago, and I joined this forum pretty much just to help figure out this very issue.
I've already talked to Vizio a half dozen times, and they'd given me different variations on the following:
1) Unplug Soundbar
2) Hold soundbar power button for at least 30 seconds.
3) Remove batteries from remote
4) Hold remote power button for 30 seconds
5) Plug in soundbar
6) Put fresh batteries in the remote
7) Turn on soundbar using remote.
I've tried that so many different ways without success. I tried it with the subwoofer off, and with it on. I tried pressing every button for 30 seconds while unplugged/batteries removed. I tried leaving the batteries removed and bar unplugged for an hour.
Heck, I even both a 12 pack of AAAs just to rule out batteries.
The best I could ever manage was being able to turn the sound bar on ONCE and ONLY once after leaving it for an hour.. It was unresponsive after that.
So they sent me a new remote.
Same thing. I let them both sit for an hour, and best I could manage was being able to turn it on ONCE with unresponsiveness following that.
I also confirmed that both remotes were sending out a signal (looked at them through the facetime camera on my iPhone.)
But I don't think I tried leaving the batteries actually in the remote when removing power from the bar...
I'll need to try that once I get home from work. I'm really hoping its just some weird quirk I need to work through, and not a problem with the IR receiver, because I really don't want to have to deal with sending it back to Vizio for a replacement. I'm almost wishing I had filed for an exchange on Amazon back when I was still within the window.
Its a shame because the soundbar is awesome for what it is.