Pattern in G4 motherboard failures?

Just to add, when I say I'm a 'light' user, what I mean is I don't do gaming & don't watch lengthy video - watch lots of short clips from news sites etc. but no films.

I do, though, browse the web for extended periods of time & use the camera quite a lot - my phone doesn't even get warm doing this. My phone gets warm during QI charging but nothing approaching hot. The only time I've had mine hot is using navigation whilst the phone sits it a wireless charging holder in my car but that's probably just asking for trouble. My last phone (Lumia Windows phone) used to get incredibly hot doing this & it automatically shut down a couple of times but it didn't fail.

I don't suppose we'll ever get to the bottom of it - some phones will run through battery more quickly and run hotter simply because of certain apps hammering the CPU and/or certain certain carrier versions of the OS giving the phone a hard time. I'm pretty sure Android has the same overheat shut-down protection that my Lumia had, so there should be absolutely no question of solder melting but, of course, heat can expose a motherboard defect.

I wonder what peoples' views on cases are? I know the leather backs are ultra-thin but any bit of extra lagging surely can't help?
 
With good design and manufacturing, these chips and solder joints are designed to take much more heat than they are allowed to before throttling kicks in.

Yup, sort of what I was saying but you said it better (you posted while I was answering the doorbell)
 
Yea I will be pushing the phone much harder in a few few months when I'm fishing all the time. I don't play games at all but push the phone with navigation, qi charging, fast charging, and lots of camera use. The G4 runs hotter than any phone I have had yet. But its not hot....it's more "pretty warm" to me.
 
Just to add, when I say I'm a 'light' user, what I mean is I don't do gaming & don't watch lengthy video - watch lots of short clips from news sites etc. but no films.

I do, though, browse the web for extended periods of time & use the camera quite a lot - my phone doesn't even get warm doing this. My phone gets warm during QI charging but nothing approaching hot. The only time I've had mine hot is using navigation whilst the phone sits it a wireless charging holder in my car but that's probably just asking for trouble. My last phone (Lumia Windows phone) used to get incredibly hot doing this & it automatically shut down a couple of times but it didn't fail...

I've read MANY reports of some G4's just running "hot" - and this is something that can be quantified since easy to read battery temp. It likely has something to do with a heatsink defect in a smallish number of G4's. Lots of folks have had a "hot" G4, got and received a replacement that ran cooler. My guess is the ones that run hot have a higher incidence of boot loop failure, but bootloop can happen to any of the early batches of the G4 (and unfortunately a handful of the later ones).
 
My first G4 got noticeably warm to even "hot" from time to time (I recall it most noticeably right after I got it in June, while taking pictures...it seemed to settle down over time/updates). However, it was not warm nor had been heating up even periodically right before I got the bootloop of death. It just...died.

As others have said, it's a physical problem in manufacturing. It can fail regardless of any heating issues. Heat may expand the solder and hurry the failure, but heat isn't the problem.