Tablet Computer Turns Itself 'on'

[alec_t]

What kind of dingbats would allow this to happen.

The kind which write apps which want to 'phone home' every 5 mins (I'm exaggerating a tad) to check for updates?

 

[eTech]

The kind which write apps which want to 'phone home' every 5 mins (I'm exaggerating a tad) to check for updates?

Some devices do support "wake on wifi". You might see if it's available and temporarily turn it off.

I wonder if an app may be using a "location" service?

eT

 

[fvm]

here is some random suggestion
maybe the google app is corrupted by some virus or torjan or something like that, which prevent the tablet from going into complete power down. it wakes up when app does some activity.
try detail scan

 

[eTech]

Suggestion:

1. Try backing it up, then perform a factory reset, then update the firmware, then perform another factory reset, in that order.
Then see if it still wakes up randomly.

2A. If after 1. above, the problem goes away, then restore the backup and continue to monitor.
If the problem comes back, probably one of the apps...

2B. If after 1. above, the problem comes back, then I think you've identified the problem (HW).

eT

 

[MrAl]

alec, etech, fvm,


Another question i have is about the battery power disconnect (below).

alec:
Not sure what you mean by phone home, as i thought a power down meant a power down not a conditional power down.

etech:
As to wake on wifi, i had wifi turned off before powering down so this makes me wonder too.
I expect a power down to be a power down not a conditional.
My last resort ever would be to do a factory reset because the manual says this is not a good idea for some reason.

fvm:
What do you mean by "detail scan"?

all:
Well so far after disabling some of the Google stuff i am up to a full week without it turning on by itself! I dont need that stuff anyway as the tablet is there mainly for very rare use if the power line power goes down here (we have trouble with that now and then).
I dont need to download any 'apps' or anything like that either, and what i did download in the past was from Google Play Store with only one exception and that was from a reliable source.

So i am hoping this problem is solved at least for now. This is the longest it has went without turning on by itself as before it was roughly after 1 or 2 days of being completely powered down.
It's been a week now so that's a good sign.

About the battery disconnect, i am tempted to just throw a regular small power switch in there.
This would turn the battery power off completely becuase it would disconnect the battery from the circuit board manually like with a little slide switch or something.
I was wondering if this would upset something about the tablet or it would work normally once the switch is turned back on.

 

[alec_t]

alec: Not sure what you mean by phone home, as i thought a power down meant a power down not a conditional power down.

I strongly believe tablets have only 'soft' power switches, i.e. buttons which activate an 'interrupt-on-change' function in the micro; all power on/off switching being done by FETs under the control of the micro. The micro sleeps until it receives an interrupt or until some scheduled event occurs. I've no knowledge of the Android OS, but I'd put money on one scheduled event being to try to report back to Google (phone home), which would require some components being turned on.

 

[eTech]

alec, etech, fvm,


Another question i have is about the battery power disconnect (below).

alec:
Not sure what you mean by phone home, as i thought a power down meant a power down not a conditional power down.

etech:
As to wake on wifi, i had wifi turned off before powering down so this makes me wonder too.
I expect a power down to be a power down not a conditional.
My last resort ever would be to do a factory reset because the manual says this is not a good idea for some reason.

fvm:
What do you mean by "detail scan"?

all:
Well so far after disabling some of the Google stuff i am up to a full week without it turning on by itself! I dont need that stuff anyway as the tablet is there mainly for very rare use if the power line power goes down here (we have trouble with that now and then).
I dont need to download any 'apps' or anything like that either, and what i did download in the past was from Google Play Store with only one exception and that was from a reliable source.

So i am hoping this problem is solved at least for now. This is the longest it has went without turning on by itself as before it was roughly after 1 or 2 days of being completely powered down.
It's been a week now so that's a good sign.

About the battery disconnect, i am tempted to just throw a regular small power switch in there.
This would turn the battery power off completely becuase it would disconnect the battery from the circuit board manually like with a little slide switch or something.
I was wondering if this would upset something about the tablet or it would work normally once the switch is turned back on.

Hi

A factory reset basically clears the device of any software, changes and reverts the OS back to its original factory condition.
It doesn't remove the OS. Unfortunately, I believe it's the only way methodical way to determine the problem. But don't do it without backing up the device unless you don't need anything on it.

I downloaded and read the manual but the resolution is poor so I couldn't make out some of the images.

When it powers on by itself, does it display the system logo, like when you manually power on?
Or does the display just turn on, displaying the app icons?

eT

 

[MrAl]

Hi again,

alec:
Yes i am starting to believe that too

eT:
When i put the device to sleep, i can press the power button and the screen comes back on completely and showing all the icons as normal.
When i power down, if i press the power button after that it takes about 15 or 20 seconds to power back up showing the logo for Android. It takes much longer to power up that way but it saves the battery.
When it turns back on by itself i have never been there to watch it power up so i have no idea what it is actually doing, but guessing i would say it has to do a complete power up showing the logo for Android. That's what is nutty about it.

But as i said, i think i have the problem resolved now as i have disabled some programs made by Google and the device has not turned on for a week, and that's the longest time it has gone without turning on by itself. So i am guessing that it worked so there is no need to do a factory reset which i already said i dont want to do. I would rather install my own battery power disconnect switch that completely turns off the battery physically so it is impossible to turn back on without sliding the switch to the 'on' position.

I guess i could scope out the circuit a little to find out where it turns on, then disable that, but i thought a battery power button would be simpler because the battery leads are clearly visible where they connect to the circuit board. What i fear though is that it will do a factory reset when the battery is disconnected and then connected back up. I am wondering if the battery keeps the factory settings or something like that.
I also wonder why they would say a factor reset is not recommended in the manual.

 

[eTech]

Hi again,

I guess i could scope out the circuit a little to find out where it turns on, then disable that, but i thought a battery power button would be simpler because the battery leads are clearly visible where they connect to the circuit board. What i fear though is that it will do a factory reset when the battery is disconnected and then connected back up. I am wondering if the battery keeps the factory settings or something like that.
I also wonder why they would say a factor reset is not recommended in the manual.

No...it wont do a factory reset on its own, and removing the battery won't either..it requires a specific manual key sequence.
The firmware update is similar to updating the BIOS in a computer, and you don't want to interrupt it during the update
or bad things will happen to the device.

Generally, manufactures don't recommend it because they have low confidence that the user will follow instructions.
Users say they backup their system, but don't do it correctly, or power off the device when its updating, etc., which
result in a non-working device, and a return to manufacturer.

I currently work in the I.T field, and what we would do is what I suggested in thread #24, but its understandable if you prefer the safer route and not reset it.

eT

 

[Dr_Doggy]

Power button is soft, software is capable of waking up, or powering on even, for example alarmdroid (alarmclock), apps get permissions for any resource they use, and my alarm rings regardless , as long as there is enough life in battery, if you are witnessing success odds are you got the app out that was causing it, i found apps come out completely when uninstalling , ie, all bugs come out aswell, weather they are bugs(unintentional) or viruses(intentional) . they do not embed in os like typical trojan.
im sure cutting battery will not harm(cos what happens when its too dead to fully shutdown) but i dont think u need, as you have solved problem already.
Factory reset restores device back to day one, just like my router reset. i have done it few times now but wat a pain to redownload apps. more of a last resort really, better if you can find the bad app.

 

[alec_t]

but wat a pain to redownload apps.

Is there a way to back-up the apps onto the plug-in external SD card, or some other drive?

 

[MrAl]

Hi again,

alec:
Yes you can back up the apps. You can save the file you download or you can look for where your tablet stores the apps and copy them all to another drive. The install files are typically .apk files. You might have to download a better file manager than that which ships with the tablet though, so you can reach the directory with the .apk app files in it and copy them all.

DrDoggy:
Yes the power button is soft that is right, so i guess the CPU is being woken up periodically to check for a button press. If not pressed it goes back to sleep.
If you are sure cutting battery power wont hurt i might try the hard power switch idea not only for that but because i would also like to be able to plug a new fresh battery in after it has been recharged so i dont have to wait for the one inside to be recharged all the time. This would really require disconnecting the battery too.

eTech:
Well, it has been completely 'off' for a week now so it looks like the fix worked, but im waiting longer to know for sure. That means it wont be necessary to do a factory reset anyway. If it ever came to that i guess i would have to try it though.
I kinda like the idea of a 'hard' power switch though as that makes darn sure it is off completely and can not drain the battery for any reason. I like that idea a lot
This also gives me the option of using a connector on the battery to plug in a new battery rather than recharge the one inside it, or even to replace the battery at some point if needed.
So you work with tablets every day then?

Thanks for the replies.

 

[alec_t]

you can look for where your tablet stores the apps and copy them all to another drive.

Thanks. I was concerned there might be more to it than that, e.g. disentangling things from a 'registry' (if such a thing exists in Android-land?)

 

[MrAl]

Hi alec,

Well that's the way it seems to work anyway, im not an expert on these Android systems though but i have read that installing the .apk file is the way the Android gets it's applications installed. There is other data too though that goes with it sometimes which gets removed, like account information. If you have an account of some type that requires information to log into a web site or something then you might have to reenter all of your account information because that is not stored in the .apk file. But i would think you would have written that info down somewhere and/or backed it up to a removable storage like a USB disk or two. The only way i know of to back that sort of stuff up is to type the information into a text file and then back up the text file. When you need it later you can read the text file and reenter as needed. A pain yes, but that's the only way i know of right now and probably the only way i would trust to work every time anyway.

 

[eTech]

Hi MrAl

I was reading the user guide and have a dumb question.

Just to be clear, when you want power off (full power down) the system, You:

1. Press and hold the power button till the Shutdown menu displays
2. Click "Power off" <--you actually click this right?
3. Click OK

Right?

If so, then try this:

Assuming the tablet is fully powered off, connect the supplied USB cable to the
tablet and connect the other end to your powered up PC.

See if the PC displays a dialog asking if you want to browse the storage device. If it does, then the tablet not "fully powered off".

Also,

There are a couple of firmware updates. I've been looking for the firmware release notes to determine if its worth updating
but can't find them. They usually explain what has been fixed..

eT

 

[MrAl]

Hi MrAl

I was reading the user guide and have a dumb question.

Just to be clear, when you want power off (full power down) the system, You:

1. Press and hold the power button till the Shutdown menu displays
2. Click "Power off" <--you actually click this right?
3. Click OK

Right?

If so, then try this:

Assuming the tablet is fully powered off, connect the supplied USB cable to the
tablet and connect the other end to your powered up PC.

See if the PC displays a dialog asking if you want to browse the storage device. If it does, then the tablet not "fully powered off".

Also,

There are a couple of firmware updates. I've been looking for the firmware release notes to determine if its worth updating
but can't find them. They usually explain what has been fixed..

eT

Hello again eTech,

Yes that is right, that is how i "power down".

The alternate method is to just tap the power button quickly and that puts it to sleep, but that's not a power down because that uses the battery up in about two weeks time, whereas with a power down the battery stays pretty much at 100 percent which is full charged.

Bad news though, i found out just a few minutes ago when i checked it again that it had turned on around 10am this morning. I have it set now to turn off the screen automatically but that just is the same mode as 'sleep', which will eat up the battery power within two weeks or a little less so that is not a solution.

I also realized that a factory reset is not a good option anyway because that does not guarantee that this will not happen again, mainly because i dont know what is causing it. I have to reinstall some apps, and if i dont know which one is causing this it wont help to factory reset because i'll just have to put everything back anyway.
I might have to do that at some point but i'd like to know what is causing this first so i want to do some more testing first.

So what i did next was disabled another program, Google Play Store. We'll see if that helps because when i looked at the running apps that showed up as running. It's disabled now though so we'll see.

What i suspect now is that there was more than one program starting it up. Disabling some programs might have stopped it from starting up for a while (one week vs two days) but there was still another program that would start it up. Once i get rid of all the programs that can start it up it should stop, then maybe factory reset or something like that. I am also still thinking about the hard wired power switch option, but i am curious now as to what was causing this absurd problem. If i put the switch in now i'll never find out.

I guess i could try your test, but it is totally powered down as much as you can possibly power down, so if that's not powered down then there is no way to power down completely.

I've actually programmed microcontrollers to do this very thing so i understand what they are doing basically. The uC is put to sleep, which is a very very low power mode where the battery can last for two years without a charge. But that would be the "power down" mode of the tablet, not the "sleep" mode of the tablet, which is very different and shows up in operation as very different too.
The uC is made to wake up every so often, like 10 seconds or 30 seconds. When it wakes up, it checks the status of all the sensors and records the results. Then it goes back to sleep. That whole process takes less than a millisecond to complete so the battery drain is incredibly low over the average, as the sleep power is maybe 50 microwatts and it is in the sleep mode most of the time.
So i suspect they do the same thing but i would hope they have a separate watch dog chip to do that and dont wake the entire CPU which would take more power than a small micropower uC chip. The tiny uC chip could wake up and check status, then turn on the main CPU if the button sequence was correct for a turn on. But how the apps get around this is another story.

 

[eTech]

Hello again eTech,

I also realized that a factor reset is not a good option anyway because that does not guarantee that this will not happen again, mainly because i dont know what is causing it. I have to reinstall some apps, and if i dont know which one is causing this it wont help to factory reset because i'll just have to put everything back anyway.
I might have to do that at some point but i'd like to know what is causing this first so i want to do some more testing first.

Hi

So...at the moment you don't really know if its a HW or SW problem. Might not be SW (apps) at all.
If you follow the steps in #24, at least you can eliminate one or the other..

eT

 

[MrAl]

Hi

So...at the moment you don't really know if its a HW or SW problem. Might not be SW (apps) at all.
If you follow the steps in #24, at least you can eliminate one or the other..

eT

Hello again,

Well, if i had no other test data to go on i'd think that too, but i have several weeks of test data.
Let me reiterate the history as it happened over those weeks...

To start with, it was turning on after about 2 days after being completely powered down. I didnt know it at first because i did not check it every day, just once in a while with no planned routine. Then i found that every time i checked it, it would show a running time that dated back to about 2 days after i last powered down. That tells me it was turning on after 2 days.

What i did next is i started to disable programs, mostly Google related stuff (except for Play Store). After i did that, it took a full week before it tuned on again. That tells me that disabling software had an effect so it is probably software.

Next i'll check it again in a week and see where it stands.

I'd laugh if it was built into the OS somehow or an app that came with the thing already installed was doing it. If it turns out to be too hard to solve i'll just install a hard wired switch.

I appreciate your ideas here too, and i'll have to find my USB cable and see how that other test works out too at some point.

 

[eTech]

Hello again,

Well, if i had no other test data to go on i'd think that too, but i have several weeks of test data.
Let me reiterate the history as it happened over those weeks...

To start with, it was turning on after about 2 days after being completely powered down. I didnt know it at first because i did not check it every day, just once in a while with no planned routine. Then i found that every time i checked it, it would show a running time that dated back to about 2 days after i last powered down. That tells me it was turning on after 2 days.

What i did next is i started to disable programs, mostly Google related stuff (except for Play Store). After i did that, it took a full week before it tuned on again. That tells me that disabling software had an effect so it is probably software.

Next i'll check it again in a week and see where it stands.

I'd laugh if it was built into the OS somehow or an app that came with the thing already installed was doing it. If it turns out to be too hard to solve i'll just install a hard wired switch.

I appreciate your ideas here too, and i'll have to find my USB cable and see how that other test works out too at some point.

Ok...Good luck

eT

 

[MrAl]

Hello again eTech,

Well thank you and thanks for the suggestions. I have them here now so at some point i will probably end up trying them all.

I cant believe that this has happened in the first place. Tablets should not be allowed to turn on by any program because if the operator is not around or sleeping the battery drains down and the operator/owner knows nothing of this until he/she wakes up and finds the battery almost depleted. In one case, i think it was the first time i started to realize this was a problem, the battery drained down so far that the device would not even turn on at all. Lucky it gave a low battery condition indication though, so i knew it needed to be charged. So that time it was so bad i could not even use the tablet.
What took so long for me to realize this problem at all was the fact that i kept thinking that the power button got pressed by accident. That's because in several cases i had moved it around and thought maybe the button bumped something else and that caused the turn on. Another case i had it in my pocket and it turned on and i thought something pressed the button.
But now i know for sure because i built a special fitted see through case to hold it in a position that could not possibly press the power button, and it still turned on by itself.

So maybe pass this information along to other people too and they can check if theirs turns on by itself also.

Thanks again...