[AT&T Samsung Galaxy S 4 Q&A, Help & Troubleshootin] nukesnooper:
Long story short; I sent the phone to a former NTSB investigator who confirmed what I already knew. Thermal damage.

The refurbished phone that they sent as a replacement was FULL of issues, so I had to have it replaced, as well. The camera would not focus, the sound recorder only recorded static, it wouldn't retain my preferences that I set in the phone, and randomly reverted to the default ringtone.

When I called back to get it replaced; I was greeted by a VERY friendly, helpful, and understanding representative who told me that the original claim WAS NOT handled properly. She overnighted a new phone and battery and asked me to return the original phone to a different address for examination. She agreed that they would probably just take one look at it and claim that it was physical damage. She reversed the charges for the replacement - even though I had the "Premium" insurance on it. She also noted that I had a written report with photos to verify that it was a manufacturing defect - with the obvious caveat that if there really was physical damage that I would have to pay the deductible. Naturally; I used my Sony video microscope to take photos of every angle of the phone, the edges, etc. - to prove that there wasn't so much as a single blemish anywhere on the phone that they could construe as being "physical damage" - aside from the obvious darkening to the inner plastic from the internal heat, and it was isolated to the rear of the display.

I got back in town early yesterday and the newest replacement was already waiting. I charged the battery and fired it up. So far; so good. Works like a champ. Bear in mind, it's been less than 24 hours...

Oddly; I didn't start having issues until AT&T forcefully crammed the firmware update down my throat. And, no; I had done no modifications - such as rooting or work-arounds to either phone. So; I actually have a legitimate question: Have any of you experienced any phantom issues with your S4's, post firmware (FM3, I think) update? I know that it gave me a message: "Updating Camera Firmware", and the camera would no longer focus. I took copious photos and videos with it and have saved them for reference. In the videos; you can see that the camera is constantly zooming in and out of focus - even though it was stationary, aimed at a fixed subject, and at a very reasonable distance. Many of my downloaded programs also no longer worked, or would freeze up for no apparent reason. They all had worked perfectly prior to the update, as well as on my previous Motorola Atrix HD. They still are working perfectly on the Atrix HD that I passed down to my kids, after I unlocked it, rooted it, and installed the Pac-Man 4.3 ROM. When I got the first replacement S4; it kept prompting me to download the firmware update, and I kept denying permission - in the event that I felt frisky enough to do some fancy footwork on it later down the road. One morning I woke up and it had a message on the screen: "Software Update Successful!" After I angrily cleared that screen, it gave me the message about updating my camera firmware. Now; I'd only had it a day or so, so I can't verify that everything was working properly before - it just seemed to be OK.

My next question is: Is there any way to block them from updating this phone, and constantly bombarding me and forcing me to install useless "bloatware" that I'll never use and only uses up more of my internal memory. I have the 32GB S4 so it's not a huge issue, but it's obnoxious, at the very least that they think that they know better than I do what I want to be installed on my phone. I can hide them, uninstall the updates and put them out of sight, but they're there, none the less, and I don't want them! Yeah; I know I agreed to their terms, but that just seems downright controlling and unfair. And, by the way; even if I do hide them, and uninstall the updates; they magically reappear in a few days and it seems like I'm constantly receiving messages prompting me to update them. Even if I decline; they download anyway. Sort of a "Wash, Rinse, Repeat" scenario.

OK; after my last nasty rant, I expect (and deserve) some nasty feedback, but I'd really appreciate any suggestions or insight to these issues. Any similar experiences? I'd been foaming at the mouth waiting to get this phone, but it seems like it's been one terrific headache after another. I've only owned Motorola phones (since 1985) until now. Motorola now seems lackluster compared to the newer models or I'd have never jumped ship. Now; it seems like I made a $700.00 mistake. I really hope I'm wrong and just unfamiliar with other manufacturers equipment. Save me from myself!

Thanks, everyone!

Nukesnooper