This maybe too detailed but - My S6 active was working fine for a few months (got it used off swappa in very good condition) and then last week while on vacation I noticed I wasn't getting service, it was getting extremely hot and was draining the battery quick randomly one night. It seemed odd since 3 others in my family with the same service were getting good reception and I had gotten good reception in that spot for some time. I turned it off overnight with similar results in the morning. I popped the sim card in my backup S4 active to get by. At the time turning it on with out the card yielded similar results. I read wiping the cache may help so I tried that with no luck. I turned it off for the rest of my vacation knowing I may need to do a factory reset. When I got home yesterday I turned it on without the SIM card and showed the triangular bars (instead of circle with a line through it) as I would expect and didn't get hot. Once the sim card was in it went back to behaving like it did (circle with line through it - no service, getting hot and draining battery quickly). I pulled off documents that I wanted and did a factory reset and initially it didn't seem to work but after about 15 minutes normal service popped up during the initial welcome/setup screens and worked all night just fine. I reset the phone this morning and it again went back to acting how it was. I figured I could do a factory reset again but would be nice to not have to do that each time the phone is turned off ( if that is what brings these symptoms back). Just curious if anyone has experienced this or may have any ideas.