
Originally Posted by
Mrhelper
Most of this thread discusses a problem where users were having to force their tablets to power down after some period in sleep mode, and the problem in most cases was probably an app that was hanging and preventing each user from accessing the GUI to regain control of the device. It would not necessarily have been caused by the same app for all users. This condition can be caused by any number of apps, either built-in or loaded by users.
If your tablet is a year old, it is possible that the battery is dying, so you should check the state of the charge when this happens to rule that out. It's more likely that you are encountering a problem with some app or built-in tablet software though. As I noted above, this could be something you installed, or something that came with the update from Acer.
You need to verify whether or not your tablet is becoming hung while in sleep mode. The next time you encounter the problem, press and hold the power button for at least 5 seconds. If you feel no vibration, then your tablet was apparently on, but likely hung on a bad process/app. When the unit is already on, and you then hold the power button for 5 seconds, it forces the tablet to power down unconditionally. It does not vibrate as it does on a normal shutdown. The operation is similar to pulling the plug on a desktop PC -- i.e., it simply removes the power without shutting down any of the programs or doing any normal shutdown preparation/cleanup.
After you shut the system down, then a subsequent push of the power button with a 3 second hold will power it back up, and you will feel the tablet vibrate while starting.
If this is what you are seeing, then the next step is to find and eliminate the cause of the problem if possible. Start with removing any apps that you may have loaded before the problem first occurred.
You state in your post that this started after the latest update. I assume that you mean the update to ICS. You can verify this in Settings-->About. ICS is Android version 4.0.3.
I've worked with a number of users who encountered a similar problem, and we narrowed that problem down to a sync issue that occurred while the tablet was in sleep mode. That particular problem apparently only occurs with ICS, and not Honeycomb (Android 3.2.1, the previous version before ICS).
If you are having that problem, then there are a few things you can try that have worked for others. Any one of these will prevent the sleep/sync/hang problem if that is really what you are encountering.
1.) Turn off sync for all accounts under Settings-->Accounts & sync. You can do this on a per account basis, or use the on/off toggle master switch at the top right of the screen. You email will still download when you access it, but not in the background. You can still sync accounts manually with the automatic sync options turned off.
2.) Forget your wifi connection under Settings-->Wifi. Just select a connection and press the Forget button. This will require that you set it back up, and is not a very practical option, but it does prove whether or not you are seeing this problem.
3.) Power down your AP/router to prevent sync connections. Again, like option 2, this is not a practical solution, but I mention it because it has some test value.
The sleep/sync/hang problem appears to occur as follows: When the tablet is in sleep mode, and sync is turned on, the device will periodically turn on wifi, and connect to the AP for internet services so it can sync. If it works, it completes the sync operation, turns wifi back off and goes back to sleep. When the hang occurs, the tablet will not wake up, and has to be forcefully powered off. I do not know why this happens for some user and not others. I suspect it may have to do with unique characteristics of certain networks that trigger a bug in the ICS sync services or wifi driver. It could also be caused by subtle differences in hardware between devices.
Note also that if option 1 does not work, but options 2 and/or 3 do, then the problem is likely some other app requesting and getting network connectivity during sleep mode. You'll then need to run that down by eliminating apps.
If none of the options noted above help, then you may want to try removing apps to eliminate potential causes. Some apps do not work as well as they did on Honeycomb, so even if you were running these before the update, you could have a problem with them now. For some, Chrome Beta causes frequent hangs and system crashes/reboots. Dolphin and the stock Android browser can be high background CPU consumers.
A Factory data reset may also be useful, especially if you did not do one after the ICS update.
Please post back here with what you learn. Thanks.