I had to leave the watch on its charger for 24 hours before I could get it to re-start and all that time there was no indication it was charging. The watch was in power saving mode before it died and when it started up again it was still in power saving mode. I don't know if power saving mode was the cause of it taking so long to charge or not. I won't let the battery completely drain ever again if I can help it.
Before trying this I tried using Wireless Power Share on my Galaxy S20+ and when the watch was set on the back of the phone, the phone's display said "charging" but the watch still said nothing so I knew that the watch was at least willing to take a charge.
Typically if these steps have not helped, repairs would be recommended. You can message us here with your full model code and serial number for more information: https://us.community.samsung.com/t5/notes/composepage/note-to-user-id/12031537
My 17 months old galaxy watch 46mm screen went black this morning ..i though battery was dead so I put on the charger and it showed a lightening symbol with a green circle around the face, started counting from 0 to 67% quickly and turned off display. Also charger started blinking red after a bit.
When I start it by pressing power I see the logo only then black screen and I cannot do anything , seems it is off . Also my phone is not connecting to watch.
I can reboot by hold pressing power then 3 tap it to go into hardware booting/recovery menu, it shows battery at 98% . Tried to do recovery from this menu which is supposed to factory reset, but the same happens ..it reboots , shows logo, and dies.
This is ..cant start can reset ..more like a black screen of death for no apparent reason probably a software mess up by samsung ..I see 9 pages on this thread alone, besides many on reddit ..yet no solution ...