I wanted to pass on my experience with the S3 not restarting after a power loss.
Problem
If the 5V GPIO was connected to any sensor the S3 would not acknowledge that power was on, ie, the small LED would not light and any sensor LED would not light such as a DS3231 RTC. Neither was the PORT available. Toast!
Disconnecting the 5V GPIO would allow the S3 to become ‘active’ but if you had code to verify that your DS3231 was actually connected it would freeze because the 5V GPIO module power pin was disconnected and could not power the DS3231.
Solution
Connecting the DS3231 VIN pin to the S3’s 3.3V GPIO (instead of using the 5V GPIO) would allow the S3 to reconnect if power was lost. While this ‘solution’ did work it still presented a problem with 5V modules such as a SSR. I began to think that the S3 in question had failed in some way so I retested with another S3.
(Note. The DS3231 works with either 5v or 3.3V.)
2nd S3 Test
To perform this test I decided to connect a 5V SSR with appropriate loads attached while still using the DS3231 RTC described above.
Results
Everything worked as it should. I disconnected the USB-C cable several times and never had a problem. This made me believe that the first S3 was damaged so I switched out the S3’s and was shocked that the first S3 was now reconnecting after a ‘power loss’, USB cable being disconnected.
Clarity
I do not press any BOOT or RESET S3 buttons during any of this. Everything was/is identical for both S3’s.
I am heavily invested in S3’s so I was determined to solve this issue. Hopefully this will help someone having this same issue.
Thanks.