Tablet Computer Turns Itself 'on'

[Electroenthusiast]

Just check whether updating all the apps to latest version solves the problem. There might be a BUG in old versions.

WARNING: Be careful while updating, you may lose some data(not in most cases), UI of latest version might not be as same as before.

 

[alec_t]

This may be relevant:
https://www.purdue.edu/newsroom/research/2012/120613HuSmartphoneBugs.html

 

[MrAl]

Hi alec,

Thanks much for posting that link. At least some definitive proof that this kind of bug is more widespread than just a couple Android products.

They are saying that it is a bug in the software code written by app writers. Pretty amazing that the mistakes always lead to waking the device up when it is not supposed to be turned on.

Whether this is the exact problem i am having or not remains to be seen, but knowing that it affects other devices too is good to know about.

It's funny too that my cell did this as well, but i found that was caused by the power button getting pressed without realizing it, so a hard shell case was the solution there. This Android Tablet however is not so easy.

Thanks again for posting that informative link.

 

[KeepItSimpleStupid]

My early Android cell does something similar, I'll see it reboot every once and a while and it's just lying on the table next to my bed.

 

[alec_t]

Serendipity. I came across that linked article while googling for a totally unrelated 'bug' in the 'bug transmitter' thread.
If you haven't tried already you should be able to pin down a buggy app by backing them all up, uninstalling them all from the tablet, then reinstalling one by one, monitoring as you go.

 

[MrAl]

Hi again alec,

Yes that's a good idea, but the trouble is the problem takes 8 days to analyze. In other words, if i removed one program at a time i would have to wait 8 days to see if it helped or not. I dont have a super large number of programs in there, but there is enough that it would take maybe 6 months to completely troubleshoot that way and i am not sure if 8 days would be enough to be absolutely sure the 'bug' went away.

But even more to the point, if it is a program i really liked to have in there (some more important of course) then what would i do then. Maybe contact the author if i can. Just not sure if it is worth all that trouble and careful testing. I'd probably have to give it longer than 8 days too just to make sure, so we are talking about a very long term and careful testing plan. It's doable for sure, but not sure if i want to dedicate that much effort to finding this bug.

Your thoughts on this much appreciated.

 

[alec_t]

Ok then, it's "hack a hole in the tablet, chop the battery lead and wire in a proper switch" time .

 

[MrAl]

Hi alec,

He he, yeah. It looks like that's the only real way to handle this, without spending a lot of time troubleshooting.

This seems like it could be something that a virus program would not detect either.

 

[alec_t]

This seems like it could be something that a virus program would not detect either.

The 'wakelock' API is obviously intended for developers to use legitimately, so presumably an anti-virus program wouldn't block its use.

 

[JimB]

Yes that's a good idea, but the trouble is the problem takes 8 days to analyze. In other words, if i removed one program at a time i would have to wait 8 days to see if it helped or not.

Why not try something like this:

Say you have 20 programs, unload 10 of them.
Is the problem still there?
No, then the problem is with one of the 10 which you unloaded. Reload 5 of them and try again.
Yes, then the problem is with one of the remaining programs. Unload 5 of them and try again.
Repeat this process until you have isolated the faulty program.

Trouble is that this could get confusing if there was more than one faulty program.

JimB

 

[Dr_Doggy]

another thought i just had, if you get eclipse compiler with android sdk , you plug in the usb and turn debugging in dev options, i have noticed in eclipse, when i am attached with android even on "desktop", eclipse console window spits out a fair bit of data, idk if its big enough for a 24 hr log though , or if there is a way you can export, but just an idea that may help to sniff background processes, our mysterious event process may pop up at the 8 day mark.

 

[MrAl]

Hi,

Thanks for the ideas. I am still thinking about how much more i want to get involved with this. It's a big pain to test because it takes so long to get a result for a given test.

What would be interesting is if i could build into the case a sensor to sense when the screen comes on, then have the power button pressed with a controller. Only catch is that when i shut down (not go to sleep) after pressing the power button for maybe 1 full second, a message box comes up on the screen that asks for a confirmation. This means i would have to also have a control that 'presses' the touch screen button. That button always comes up in the same place on the screen which is convenient, but i would have to make an electronic pad of some times that could activate that button electronically rather than with an actual press with a finger. I havent looked into how to do that too much yet, but it would be interesting to find a way to do that.

It is a capacitive touch screen so anything that could activate it would have to be able to interface with that kind of touch screen. I've read about N channel MOSFET's being used for this but i'd have to test it and get it working.

 

[MrAl]

Hello again,

Well it's been quite a few months now where every 7 or 8 days i had to check to see if the tablet has turned itself on, and no response from the manufacturer so i just got plain sick and tired of checking it and turning it off and recharging if needed, so i pulled the plug.

Today again i missed the turn on day and it was already down to about 65 percent charge where 100 percent is just after a charge. I decided it was time to try the ultimate: disconnect the internal battery.

The result was better than expected, although the wiring is very small and it's short on space inside the case. I successfully disconnected the battery for several minutes and then reconnected and booted up and all the apps where still intact. I had wondered if i would loose any apps if the thing did a self reset of some kind without the battery when it was later connected back up.

I installed some longer wires to the battery and circuit board and now all i need is a good reliable on/off switch. I guess it will have to mount on the side unless i can get a real small one that mounts on the back of the case, recessed, which would be very nice really.

So now i say goodbye to that checking every week to see if it turned on, and i can finally put it in the nice hard shell case i made a long time ago and not worry if it will turn on again. Now it can not turn on unless the two wires are connected, which will be a switch soon.

I pity anyone who runs into this too. The only other workaround really is to leave it plugged into the charger 24/7 which i did not want to do.
But also in the process of reading about problems like this on the internet, i found that people are a little bothered because they can not replace their internal battery without sending it back to the manufacturer. That's not right at all. They dont even sell replacement batteries like they do with cell phones and cameras. It's like the manufacturers figured out a way to make more money by forcing people to service their device maybe once every two or three years as the batteries can becomes much less effective after aging.

If any readers out there have any problems with your tablet i'd like to hear about them if you care to post here or in another thread. Especially problems with the battery like it starts to run down much faster than when it was new, as that is the sign that the battery is getting old and will need replacement.

 

[KeepItSimpleStupid]

Mr Al:

Unfortunately, I have two Toshiba laptops of the Satellite A665 variety. One was bought new and suffered from w/ top cover replacements, 1 motherboard replacement, two keyboards.

Audio has been an issue since day one, but you can;t pin that one one anybody. Nobody cares what 0 db is. All i can say, is that it isn't as loud as a Compaq Prasareo I owned. I have no way of knowing or verifying the specs.

In any event, there was an intermittent non identifiable keyboard issue that wasn't fixed with a firmware update, or a new motherboard or two new keyboards. ]

The LEFT-SHIFT does work correctly using an external keyboard.

All I could really say is that it appeared that a Left-Shift R was sometimes interpreted as a Control R in Firefox and there were other "odd" issues with Excel and Microsoft Word in Windows 7. I could not make anything bad happen, it just did. I have a good reason to type at least one capital R in any email. There are not too many sentences or words that begin with a capital R, hence, "there isn't a problem". Other people have the same problem.

Well, finally I could make something bad happen under Ubuntu Linux and LibreWriter. A LEFT-CONTROL-U is supposed to underline in that application, however it seems to change the magnification as well.

When I was doing some research, I found that keeping NUM LOCK on, fixes the issues.

More data is here:
**broken link removed**

Toshiba, seems to have no real interest in their products or their customers when it comes to computer stuff. They seemed to be pretty good with just a hard drive issue unrelated to their computers. There seems to be no way to fix their attitude.

 

[MrAl]

Hi,

I disconnected the tablet battery completely by cutting one of the wires that goes between the circuit board and the battery, and the tablet evolved an arm with two fingers and twisted the wires back together, then turned itself on again !! Ha ha, a joke of course but after dealing with this tablet i would not be surprised if this really happens at some point

The real problem was that if i miss the turn on time (in order to turn it off quickly) then the battery runs down and that eats into the charge/recharge cycle life which of course means eventually the battery does not work anymore. I have read that the Li-ion and similar batteries "age" anyway, even if not discharged and recharged several times, and that is equivalent to a loss of cycle life meaning the battery life shortens by just sitting there. I have not observed this in real life however after many years of using Li-ion battery cells (the single cells). My cells usually work ok for a min of 5 years i'd say. I havent done any careful, organized testing for this though, but then again i have not had to buy many cells over the years so they must be lasting longer than 2 years.

Wow, after reading your post i guess i dont have feel as bad now as you seem to have your battle with that tablet and it makes my problem look like almost nothing. The problems you are having sound pretty crazy really.
I have some problems too with the 'built in keybaord" (which is just software) but it's mostly because i hit the wrong key sometimes because it's so small, and the lake of "arrow" keys really bugs me. When i use a physical keyboard though it works pretty well.
One of the reasons i bought this was because it was supposed to have an HDMI connector too for a larger manitor, but it did not really have that so im stuck with a tiny screen when i use it.

 

[alec_t]

Do you know the current draw of your tablet? Finding a tiny switch to make/break significant DC current could be problematic. Perhaps use the tiny switch to control a FET doing the make/break?

Edit: Another thought. Does the tablet have a clock/calendar function which requires the battery to be permanently connected?

 

[MrAl]

Hi alec,

Some good ideas, better than i had and i'll explain.

First, yes, the current is max about 0.8 amps when booting up and about 0.6 amps when running normally, and about 60 microamps when shut down. I did not measure the current in sleep mode yet but maybe next time as it is easy to measure now with that one battery lead cut for the switch.
I think i have a small switch that will handle this, probably good enough for now, but yes i can look into the MOSFET solution too with an even smaller switch in the future.

As to the other thought, that's yes too, it does have a built in clock calendar and yes it requires battery power of course to keep alive. This is where the downside to disconnecting the battery comes into play. The real time clock shuts down and resets to August 2011 (i think it was 08/08/2011). That means on reconnect and power up the calendar and clock are way off. This would be a big problem if i had to use the tablet more often because i would not want all my files saved to be saved with a date of 08/08/2011 unless i first set the date each time. I'd have to turn on the switch, power up, then set the date then set the time to get around this.

So the battery disconnect for complete power down (and absolutely no self turn on ever) works very nice, except for the drawback that the date and time get reset so they are way off next time i power up. Perhaps i'll look into setting these via microcontroller in the future somehow, but right now it's not too much of a concern because i dont have to use the tablet that often.

The other upside now (or at least soon) is that i can connect any Li-ion battery to the tablet that i want to. I have several batteries around from other stuff i use (mostly flashlights) and any one of them would run the tablet. I have to connect one more wire to the board to get this functionality but that's not a big deal now.

One other thing i should mention is that my tablet came apart by snapping apart the bottom plastic case from the top plastic part of the case. I saw on YouTube that someone had taken theirs apart by pulling off the TOP display plastic (clear plastic). Doing it that way can be very hard, so i would have to recommend trying to get the bottom off instead. It could be very hard to get that top plastic and touch screen back together again perfectly.
The plastic case parts snap apart much like a modern hand calculator or IR remote control. There are little nubs that fit into little grooves inside the case near the edges of the plastic and that's what holds the two halves together.
The top clear plastic is glued on however, so that's not easy to get off, or back on.

 

[MrAl]

Hello again,

I almost forgot to say thanks for all the ideas posted here, they helped me get to thinking about this problem even more.

One other thing i realized while thinking about doing a factory reset (and wiping out all the apps) was that if the program that was causing this problem (assuming it was a program installed later) did not cause the problem right away but maybe waited for a month to start doing it, then it oould take a very long time to find out what program was doing it. For example, after the reset i install program #1, wait 2 weeks, and nothing happens, so i install program #2, wait 2 weeks and nothing happens, so i install program #3 and a week later the problem comes back again. Now was it program 1, 2, or 3 that caused the problem? We would think it was #3 because that was the last one installed, but it could still be program #1 with a delay or #2 with a shorter delay built in.
So really maybe the only practical way to do this is to UNINSTALL programs one at a time and see what happens after two weeks. I could do this using a binary search strategy but that would mean reinstalling several programs if i did not get lucky with the guess of uninstalling several of the programs at one time, if one of them was the right one. I would assume that uninstalling completely deletes the whole program and any of it's effects but im not sure about that either.

 

[alec_t]

If you go to Settings/Application manager, then tap on an app and check its Permissions you can see if it is allowed to 'prevent tablet sleeping'. That may help to identify a rogue app.

 

[MrAl]

Hi alec,

Yes thanks for the idea. I checked, and there are several apps that can "prevent tablet from sleeping".
The only problem is that the tablet is not sleeping when i power down.

To sleep, i can just let it stay on for a few minutes (like 15 minutes) and then it goes to sleep, or tap the power button quickly.
To power down however, i have to press the power button and hold it in for a full second or two and it prompts with "Power Down?" and i have to hit "OK" to actually power down. I know this is different than sleeping because it only draws 60 microamps.

So there should not be a problem with preventing it from sleeping, it would have to read something like, "Prevent tablet from staying off", or maybe "prevent tablet from powering down", or "Prevent tablet from staying powered down", or "Allow tablet to boot up".
There is another kind which says, "Start automatically at boot", so it seems to know the difference between sleeping and booting.
It takes a good 15 to 30 seconds to boot while waking from sleep happens in the blink of an eye (less than one second).
To boot back up after a power down i have to hold the power button in for a second or two, not just tap it.
To wake from sleep i just have to touch it quickly.

You did get me to think about this more and now that i have access to the battery lead i can insert a current measuring device to sense current (ha ha). That would tell me if it turned on by itself, then maybe rig up something to either shut down or then disconnect power. If i can shut it down normally i wont loose the date and time information settings.