S7 intermittent fault - how can they "repair" it?

[peterh337]

I bought mine in May 2016. It started to crash, seemingly right after the last OTA OS update. I removed various apps one by one and eventually did a factory reset and it was still crashing. It normally reboots but sometimes it just hangs. At one point it hung and the hard reset would not wake it up (most curious as I believe that is implemented with a ~10sec hardware timer!) although it did after a couple of hours.

So I took it back. Under UK retail regs they are not obliged to replace it (Carphone Warehouse) and will repair it, which takes a few weeks. I did manage to transfer the stuff from it to my previous S6, using a mixture of google drive and phone-switch. The s6 actually works better anyway e.g. TomTom satnav doesn't crash as it does pretty dramatically on v6 and the bluetooth doesn't work on TT for annunciations via the car system (TT say they can't fix it). But the S7 had a way more usable camera (much faster and more reliable focus) and some other useful bits as you all know...

Anyway, back in the shop, the phone refused to crash for a whole hour.

What if it doesn't crash back in the service centre?

Do people really repair these phones? I realise there is a way to open them without breaking them, but surely (I am an electronics design engineer) nobody troubleshoots them at component level. They must change the whole PCB, surely?

There is some stuff online about the battery data connection (to check how much is in it) intermittently failing and that crashes the phone. I certainly found the crashing related to the charge level.

What is the likely policy on a device returned with a fault which cannot be reproduced on the bench?

In my business (industrial electronics) we would replace the product. Nothing else makes any logical sense (assuming the customer exhibits signs of intelligence).

 

[Hadron]

If the crashing started after the last OTA update then the first thing I would do would be to reflash the phone - a full install rather than an OTA. I would expect an official service centre to do this routinely for any device they are given, so there's a chance that it will be resolved even if they don't find anything.

But you are correct that they will replace a motherboard rather than try to fix components. But as those cost money I would expect they'll only do that if they do identify a fault (no inside knowledge, just that I don't see them replacing the most expensive component without seeing anything wrong).

 

[peterh337]

I wonder what my best steps would be if it comes back, seems to work, I move the stuff over to it (using phone-switch mainly, plus restoring the desktop via Nova Desktop dropbox restore) and then it crashes.

Unfortunately this restarting business is relatively widespread. My S6, v5, bought April 2015, rooted mid-2015 so no OS OTA updates since mid-2015, working perfectly always**, has just started restarting, seemingly after some app updates. No idea which app - they seem to update in batches of a dozen at a time. But mostly it is ok, and the restart doesn't lose any data and importantly doesn't seem to lose the alarm clock time

** except the USB port stopped working early on. The PC sees something connected but nothing appears in Windows Explorer (one should see the two directories called Card and Phone or some such - this works on 4.4.2 and 6.x).

Incidentally is it possible for an app to seriously damage a phone? The Tomtom problem, on droid v6 (S7) manifests itself in a particularly nasty way, requiring a sequence of several hard resets to get the phone back. Obviously "software cannot damage hardware" but this phone probably contains some config in eeprom or flash somewhere which might get corrupted by a runaway app.

 

[AZgl1500]

App Updates to me are a nemesis that I prefer to avoid.

If the app has not crashed and is still doing everything you want it to do, why risk something going wrong??
I have AutoUpdates turned OFF.

I only update an app if a review of the new features, and the Reviews coming in make it sound like the update is worthwhile.

Too many young, inexperienced app developers that will just tweak up a line of code, make an error in another line, don't have the resources to test it thoroughly on a wide range of phones.......... and they just release it declaring it to be "New and Improved".

sorry, I don't buy that..... usually updates cause problems and I prefer to avoid problems.

 

[peterh337]

Good point - I didn't realise you could disable updates.

Rooting disables OS updates but you till get app updates.

How do you then select individual apps - say you want to update the satnav?

And what if an update messes it up. Presumably only something like Titanium back would be able to backup/restore a specific app and its data? But that needs rooting.

 

[peterh337]

Update: a month later, they did repair it (the main board was diagnosed as faulty so they changed it) but then it vanished on its way back to the store, so they gave me a new S7

Apart from the long repair time, a very good service from Carphone Warehouse.