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I've been having issues* with my Samsung Galaxy S4 (Rooted, Echoe rom, SCH-i545, 4.4.2) lately and have been trying to figure out why. Problem is, it seems like neither alogcat nor adb can show, that I can see, device crashes - that is to say where the entire device shuts off on its own. Plus the /data folder didn't seem to have any type of panic or kernelpanic folder (Using Root Explorer).

Is there any way I can do this? Ideally finding previous logs, but if need be I think I can recreate the problem with whatever I need installed.

*The crash seems to be caused when I switch from 4g (LTE) to Wifi naturally, such as coming home and my phone automatically connecting to my (Already known) wifi.

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  • I'm having a very situation that sounds similar to yours. Amazon Fire Phone, rooted, CyanogenMod 11, with crashes upon wifi reconnections and bad battery drain when trying and failing to reconnect to wifi. Did you ever find any underlying cause? Mar 24, 2016 at 10:54

3 Answers 3

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If nothing can be retrieved from logcat you are probably running into a kernel panic.

You could check via adb the output of: dmesg

Some devices also have a kernel feature where, on critical errors, the last received kernel message can be read from /proc/last_kmsg

Maybe this will give you some hints whats going wrong. If not you could stream the full kernel logs via: cat /proc/kmsg and reproduce the shutdown while doing this.

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    Your answer led me to this post, which let me access the log files (*#9900# menu)
    – Jon
    Jan 28, 2015 at 22:01
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Usually, when the system crashes a Popup is launched. Its options usually are Inform or Cancel. If you click Inform, an app is launched and it lets you see the Log (Which is the one you'd send to Google to inform the bug).

You cannot see the Logcat errors because when an app is compiled for release and with Proguard enabled, then the Logs sent by the app are not visible to the final user. Only for the Android OS. It's a safety mechanism.

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  • A popup isn't launched, it just straight up turns off. Is there no log at all, anywhere? Not even the slightest hint that may help me track down the exact issue?
    – Jon
    Jan 19, 2015 at 5:08
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Most likely one of your system service is throwing ANR and android is killing it to restore service. This causes device to soft reboot or shutdown. you will not see any popup(app crashed...)since your user is already killed by OS.

here are few links that might help you in getting logs:

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  • generally this a good answer providing quite useful information but in this case it does not help and some hints are not really true. As far as I know when a critical system service dies it is restarted a couple of times..if it still dies after these restarts the device will boot into recovery. Also you should be able to see a dying system service via logcat. Jan 27, 2015 at 8:28

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