I have a Gear S3 Frontier which I had been using at the pool with my kids for over 7 month every Saturdays.
It "went" into the infamous boot-loop about a week and a half ago, just after the swimming classes was over. Like most people know, with boot-loops, you can't switch it off. I tried many of the things recommended on other threads in here.
Device was about 2 MONTHS out warranty!
Boot loops for first 24 hours
Display showing glitchy artifacts (lines in wrong places) on day 2
Device still charges everytime you dock until day 7
Device miraculously connects with phonever everytime it came on till day 7
Device stopped displaying anything on day 7
I decided to go the most drastic path, I chose to open and see if the "self-cleaning" approach would fix it. IMHO, it wasn't worth it! I spent close to $30 on the screwdriver set. One of the tradies at the shop enthusiatically attempted to open it. He did but, tightened the screw so hard, I easily got the screw stripped on getting home. After taking it to many stores; out of information that Samsung don't honor water damage.
Stuck, I decided to head to Samsung repair centre to have a go and hear the NO "officially." Phone was admitted.
About a week later, I checked in with the repair center who confirmed, moisture damage or something which I have no clue, about 5 days later.
Condition Code: 1
Symptom Code: A51
Defect Code: A
Repair Code: A
On the 7th day at the repair centre, I got notification to come pick up my watch.
I got the biggest surprise of meself!!!
New Watch Body!
New Watch back cover!!
I took the wrapping covers off myself. About the only old thing were the straps.
My Summary: Before you write Samsung off, give them a go. In my experience, SAMSUNG when over and beyond and gave me a (New) watch! Without having to pay!