@Ben The watch doesn't have to be in warranty, after my update my out-of-warranty watch did not boot up and will not be charged. I called Samsung and they will try to get you to buy a new watch but I said why should I pay when your update caused my watch to stop working so they then fixed it for free.
Thank you so much for this. I came THISCLOSE to buying a new 5 and came across this video. I had cleaned the watch back previously but I cleaned it REALLY good this time and cleaned the charger. Used a different block that I didn't try before and it worked!!! You saved me a few hundred bucks, thanks buddy!
This video could've been a title: "Hey Everybody! Press the button, if nothing happens, means the watch is not registering that you're pressing the button. Thank's for reading."
I called Samsung care and they fixed my watch for free. I sent my watch last Tuesday, they received it Wednesday by Thursday the watch was being sent back to me. I have received it and thank you to the person who posted about this info.