[Galaxy S III General] QorbeQ:
It's a shame that this post has been mostly ignored in favour of the "SDS" one, but I do actually believe both issues are related. My I9300 is running stock - always has been - and suffered with "proper" SDS last November.

The initial symptoms were that my previously perfectly-behaved phone would would randomly FC apps that didn't before, and some of my photographs and video taken on the phone suddenly became corrupted and unusable.

Finally, one Saturday morning, I woke up to find the phone stuck in a boot loop, going from the "Samsung Galaxy S3" black-and-white boot scree to the first blue sweep of the Samsung logo, then reboot. It would power-off and power-on and I could enter ODIN or recovery modes fine, but it wouldn't boot any further.

I managed to get my photos and stuff off the phone through USB in recovery, and decided to wipe and flash the same stock ROM via ODIN.

This process failed - it couldn't partition the device correctly. None of the flash counters were reading anything so I popped it into my local Vodafone shop where they said it just needed the firmware popping back on and they'd have it ready in an hour.

I went back and they said they hadn't been able to load the software and it would have to go off for repair. *sigh*

It came back about 5 days later with a repair report stating that they'd replaced the "main board" - presumably because of the eMMC lockup bug.

It was only after this that the whole "Sudden Death" news came about and I realised what had happened to my phone. The eMMC check app says that my new controller is the same "faulty" version so I've been waiting with baited breath for "safe" official firmware.

The update system threw XXELL5 my way just before Christmas, and I thought that was that, but a coule of weeks ago the phone started hiccuping again. I knew I'd seen this before and my heart sank.

Last week another update was available, this time XXELLA. Since then, all hell has broken loose on my phone. It is locking up about 5 times a day. Initially, I was rebooting it manually (by holding in the power button). Tuesday morning I was woken by my wife saying "shouldn't you be up by now?" - glanced at my phone and it was frozen on the black-and-white boot logo - no alarm! Arrggh! It's dead!

Powered off, back on again and it booted fine. Hmmm, this isn't quite the same as before then. Having seen the advice about leaving it when it's locked, I've been doing that religiously and, so far, it's always woken up again by itself, but it's definitely indicative of a fault somewhere.

I've tried to check what's happening with adb logcat (I'm not rooted - fully stock - so can't see dmesg) and there is always some sort of I/O error when the freeze happens - often an sqlite database. Then, a couple of days ago, three photos and one video suddenly became corrupted.

I've realised that there are two issues, and only one of them has been "fixed".

The main problem, I believe, is that the flash memory is dying quite rapidly. We all know that flash memory has a limited write life, and wear levelling is supposed to extend that life beyond the typical lifespan of a device (say 5 years for a PC SSD drive?). For some reason, the flash in these devices is wearing out MUCH more rapidly.

The "faulty" eMMC controller obviously had a problem when dealing with faulty flash cells and would get stuck in a permanent loop, bricking the device. As far as I'm aware, the "fix" that has been applied prevents this permanent loop. The system still needs to try and handle disk errors with the flash memory, but it's not a permanent freeze any more and eventually (once it's finished dealing with flash faults - often unable to recover the problem) the system will break out of the freeze and carry on as before.

Sometimes this means that an app has bombed out as it couldn't read it's data correctly, but most people would either have forcibly rebooted their phone, or not notice as that app would just restart next time they used it. Sometimes, however, it means that something more important has crashed due to the disk I/O problem, resulting in the phone needing to spontaneously reboot itself.

What this boils down to is - yes, I believe that there has been a fix applied for the "faulty" eMMC controller getting stuck in a permanent, irretrievable loop. But no, I don't believe the actual original problem has been addressed - namely that the flash memory is dying at an unacceptably fast rate for ... well ... who knows what reason.

I do have a theory on that too. Recently a friend of mine was looking to change his laptop hard drive for an SSD. I investigated for him and decided that the Samsung 830 series would be his best bet, if he could get hold of them. And why not the newer 840 series? Well - that's purely because the "consumer" version of the 840 uses Samsung's latest triple level cell flash memory. Newer, faster, cheaper to manufacture almost certainly but ... more importantly in this case ... less resilient. How does 1000 write cycles grab you? They claim that the wear levelling algorithm in the drives mean that their lifetime is still pretty reasonable, but I'm not convinced in the real world.

Any idea what flash they use in the S3? I have no idea, but I betcha it's something (a) cheap and (b) new(ish).

I'm now at a bit of an impasse with my phone, however. When I returned it for repair last year it was properly frozen. No-one could do anything to fix it, the flash wouldn't format or write firmware - the only recourse was replacing internal hardware (or the entire phone).

This time, however, it works ... sort of. I'm occasionally losing photos I've taken and occasionally finding it's locked up and occasionally having to wait for it to recover. No repair centre has the time to "live with" my phone for half a day, waiting to see what happens with it - and even if they did, they'd blame a rogue app or "something left over from the upgrade" - they'll just factory wipe it, maybe flash the firmware and send it back again "repaired".

It's tempting to "lose" it and pay my insurance excess ... but even then, I won't know when the problem will strike again - but that's the thing ... I'm certain it would be back.

I used to love this phone. Now I can't rely on it. I can't rely on it storing the photos I take with it. I can't rely on it ringing when someone calls. I can't rely on texts getting through to me on time. I can't even rely on it waking me up in the morning.

It's sat next to me now,lying on the desk with the screen all shiny and black. I have no idea if it's fine, or frozen. Is someone calling me right this second? I have no idea. Oh, there we go - pressed the lock buton - it's awake. I shouldn't have to check my phone every ten minutes to see if it's working or not.

*sigh* sorry - rant over.

Suffice to say, that's my take on it. If I thought it would help diagnose something "fixable", I'd root and see what dmesg is doing, but I'm convinced this is hardware and I'm also certain that Samsung aren't going to take the blindest bit of notice.

I'm pretty sure there will be more and more people complaining that their phones are misbehaving over the next few months, but it's vague enough of a problem that the "repair" will be wiping - just long enough to take them over the first year warranty...