Power surge vizio sign lit n blink but wont power on

I would say its most likely the power supply. Quite often after a power surge this can happen. Another option could be that the surge just blew the fuse on the power supply board and replacing that may be all you need. That said, usually you will get no signs of life at all if the fuse blows.

The fact that you still have power is not a good sign. It means the surge may have gotten past the power circuit board. It's possible the power circuit board did get damaged, and is simply not feeding current to other boards. Anything past the power board will require professional testing, and assuming a bad power board is a big risk in terms of cost of replacement. In short, it is not a promising situation.

does it have power? check for the power led indicator if it lits up. Look for signs on the power cord if it has some exposed wires. If you have a multimeter reader check for continuity problems.

Sounds like you had a high voltage power surge just before going out
Are u using a high grade reference center or surge stage 2 or 3?

Does power indicator lit if tv plugs in?
This will confirm that power outlet is fine and tv getting power through ac cord.
Does power indicator blinks?
If it is blinking that means tv got some internal circuit problem that could be defective power supply board or bad back light inverter board.
Visual check by local tv repair shop would be good to rectify what board need to be replaced to fix the problem.

For the 46" TV, it sounds like the main board is bad.

For the 50" Vizio: is the LED light on?

IT SHOULD BE UNDER WARRANTY. TAKE IT TO AN AUTHORIZED VIZIO SERVICER.