I went swimming with the watch and put it in "water lock" mode. After swimming, went to sauna and after few minutes, I sow that there's a message that the device is overheat.
I couldn't change the black screen but occasionally, it would show the full display of the watch and turned off again.
After few minutes outside of the sauna room, I got a message on the display that temperature is fine (or something like this) but still went to black screen (off?).
Pressing and holding the "power (home) button" would sometimes give a message on the display with the Samsung logo but, then black screen again.
The watch cannot be charged. After few seconds on the charger, the red light is blinking.
Is there a "hard reset to a situation like this?
Any other suggestions?
I can tell you right now the watch is water damaged and you'll need to replace it as it sounds like the water has gotten to the board. I've had phones come in with the same overheating and no charging issue after exposure to water and they're corroded on the inside, I'm positive the watch is too. I'll tell you like I tell a lot of customer who come in with water damaged devices:
NEVER UNDER ANY CIRCUMSTANCES SUBMERGE AN ELECTRONIC DEVICE IN WATER OR EXPOSE IT TO LIQUID.
I know that phones and other smart devices advertise water resistancy (not that the devices are waterproof) but I'm telling you as someone who sees this nearly everyday you never want to expose it water (especially chlorinated) because there is always the risk that the device you paid hundreds of dollars for can be permanently damaged. The OEM will NOT cover this under their warranty, so they don't even stand behind the IP ratings they paid for. No hard reset is going to reverse board damage and I don't think you'll be able to find a shop willing to try to open it and do a board cleaning.