After some Googling and reading some posts on this forum, it turns out that some people are having issues where their ZenFone spontaneously reboots at night during charging.
I'm making this topic to post my findings, as I was having the same issue. In the hopes that ASUS picks it up and can release a fix for it.
From my own tests, it seems that this only happens for me when the phone is charging overnight (wired, or wireless, doesn't matter) and either the WiFi or Mobile signal is weak. Last week I was abroad on a location with very poor mobile signal. There, my phone rebooted pretty much every night. Back at home, the issue resolved itself. Until I made some changed to my home WiFi and I had very poor reception in the bedroom for a few days. During this time, I saw my phone constantly reconnecting to the WiFi and it would reboot some time during the night when charging. When the WiFi issues were resolved, and I had good signal again, the issue went away and my phone now no longer spontaneously reboots.
Your mileage may vary, but for me at least it seems that the issue only occurs during this particular scenario. Hopefully anyone else or ASUS can reproduce and come up with a fix for the issue?
Could you please share a log for the issue?
Please follow the below steps to enable the built-in log tool (Bug reporter).
1. Open “Calculator APP”
2. Enter “.19595+=”
3. Select the Log type according to the type of issue you want to capture. “General cases” will work for most issues.
4. After your selection the log tool will exit so you can duplicate the issue or wait for it to happen. Try to use the screen recorder to show your issue when possible. If you can't screen record your issue, then please take a screenshot right after the issue has occurred (as a timestamp) so we know where to look in the log.
5. Navigate back to the log tool via calculator and Tap "FINISH AND SHARE".
6. It takes several minutes for the log to generate. You can exit and do other stuff in the meantime. A silent notification will tell you once the process is done. Tap the notification and then the share button to upload the file to Google Drive and share the link with a moderator. Just make sure to change the permission first so that everyone with the link has permission to view it.
Note: When you're no longer planning on logging your device, enter “.09595+=” in the calculator and the log tool will stop as well as deleting all stored log files. Make sure to share via calculator. The files found in internal storage -> asus_log are not the correct files (they are only 1.2kb)
Thanks for the reply and procedure.
Unfortunately I have not been able to reproduce the issue since, now that the WiFi situation is improved and difficult to undo again. Hopefully someone who still has this issue might be able to collect some logs?
Just had the phone spontaneously shut down on me again. Just lying on my desk, not charging.
And again, it failed to boot normally after holding the power button. I have to boot it via Volume UP+Power to boot in Recovery and start the phone from there.
I can't keep the logging tool running forever in the hopes of catching this once-a-week event as they would become massive in size (or are they overwritten cyclic automatically?). Does the logging tool even survive a reboot/shutdown?