Apple TV doesn´t work at all after updating firmware!

The update didn't apply correctly. You need to restore via iTunes.

Apple TV (2nd and 3rd generation): Restoring your Apple TV

Make sure you follow the steps correctly (unplug all cables, connect micro usb, then reconnect power)

Connect directly to a computer, not a keyboard port or USB hub. Try a different cable

Mine is doing this too. I restored it twice but it is still not working. Any suggestions?

My 3rd Gen ATV is not responding at all, first to its remote control, 2nd to itunes after trying to restart it tru the set up posted in Apple Help. it does not blink, doesnt appear at all in iTUNES.

Weird. Hope someone out there can help.

See above

Did it restore successfully? If it did and the issue persists then you will need to take it to Apple

Tried all possible online help available. from apple to google to youtube. It just does not blink and turn on. Worst, its a month aftter its first anniversary of purchase. Very good apple.

Did you restore it using the steps outlined above? Was it successful?

If so I would suggest taking it to Apple, they are usually good about replacement.

I have tried the steps you mentioned before going on this forum. My worry is only that apple will not replace it because its past the normal warranty of 1 year. the apple TV just broked automatically a month after its first anniversary

If it was the same situation as the first poster then it would due to the firmware not applying properly. That's usually a result of a network drop, interference or environmental issue (i.e. power outage) that occurs during download.

As I say Apple are usually good about replacement on these, you would be guaranteed if it were under warranty but there's still a good chance and it doesn't hurt to go in.