
Video: Nexus 7 touchscreen defect - ukdm
http://www.geek.com/articles/gadgets/video-nexus-7-touchscreen-defect-20120720/
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brittohalloran
I've also had issues with a slightly unresponsive touchscreen on my Nexus 7.
Touches that (based on smartphone experience) SHOULD have registered, don't.

Separately, and more seriously, this morning I flipped the screen on (after
using it for a while with no issues), and the screen was completely washed out
to the point where you almost can't see what's on the screen [1]. I obviously
tried adjusting brightness right away, powering off and on, etc. Nothing. This
seems fairly widespread [2] (lots of reports on forums etc., then again a lot
of people bought it and only people with issues complain). I will be trying to
tighten up the screws inside, and making sure any connectors are seated
properly, but sending it back for a replacement if it that doesn't work.

[1] like this: [http://www.nexustablets.net/forum/nexus-tablet-site-
news/650...](http://www.nexustablets.net/forum/nexus-tablet-site-
news/650-nexus-7-screen-washout-ghosting-potential-widespread-issue.html)

[2] more reports here: <http://forum.xda-
developers.com/showthread.php?t=1749849>

~~~
silasb
I have noticed the problem with the edge of the screen not being responsive
since I've had my pre-order one since 17th.

My own gripe is the ghosting/flikering that was demonstrated earlier this week
or last last week. When I turn the screen on and start reading Currents, as
soon as I scroll to a new page I will see the screen flicker a little bit.
This is after the screen gets refreshed with new content.

Umm reading through what I wrote makes me thing it is the auto-brightness
changing.

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jsight
The Nexus One used to have touchscreen problems as well:
<http://code.google.com/p/android/issues/detail?id=6296>

Hopefully Google/ASUS will respond well with fixes. It really does sound like
a heat-related issue affecting the digitizer.

~~~
lewispb
I don't think this is heat related as switching the screen off and on again
clears the issue.

Looks like a software defect which will hopefully be rectified with a hastily
developed update.

~~~
mistercow
>I don't think this is heat related as switching the screen off and on again
clears the issue.

I'm talking based on a very rough understanding of how capacitive multi-touch
works, but it seems plausible that on restart, the screen calibrates itself
for the current environment, "zeroing" itself according to the capacitance it
is currently seeing, and that that zero value is no longer accurate once the
temperature changes significantly.

~~~
joezydeco
As someone that works on projected cap screens, I can say that you're pretty
much on the mark. You normally take a "baseline" or background read of the
sensor's capacitance and then use the signal level _above_ that baseline to
determine the presence of a finger.

Now if you don't keep dynamically adjusting that baseline to the environment,
and there are many different approaches on how to do this, you could start
seeing false touches or no touch at all.

That being said, _every_ modern manufacturer has algorithms like this in
place. So another place to look is construction. When you see problems on the
edge, is the flexing of the screen causing your glass to delaminate from the
sensor line? Perhaps power cycling fixes it (for now, because of dynamic
baseline recalibration), but eventually the circuit could completely fail from
a mechanical point of view. I'm curious to see if the problem grows and if it
eventually results in failed units that software can't recover.

{edit} Looking at the teardown, Nexus7 is using an Elan controller. Out of all
the teardowns I've seen this is the first I've seen from them in a major
product as opposed to TI, Broadcom, Atmel, or Cypress. This might get
interesting.

~~~
Splines
Interesting - I have an iPhone 4S, and I've noticed that if it's in my pocket,
the touchscreen is really unresponsive. I get a call, pull my phone out, and
it takes several tries for the "swipe to answer" gesture to succeed (usually
the iPhone will drop my swipe about halfway through).

The incoming call probably makes this worse, when I am not in a call I don't
recall ever having trouble unlocking my phone with the same gesture.

~~~
joezydeco
Was the screen facing your body when it was in your pocket? You just had a
_very_ large capacitive body next to the screen for an extended period. What
you described would make sense if the iPhone's screen recalibrates itself.

~~~
Splines
Yes, I always keep it facing inward to protect it should I do something like
walk into table corner.

It's a bit of an annoyance, but thankfully is pretty temporary. I've gotten
close to missing calls before, but haven't actually missed one.

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dkhenry
I know I can't post on geek.net, but since apparently one data point is enough
to ruffle feathers, my iPad had a non working rocker switch on the side ( the
one that you can use to lock the screen or mute the tablet ). I had to send it
back to get replaced. At the time I told everyone they should be concerned,
clearly one failure indicates a real problem with the device.

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jasonkolb
I have this same issue. I think it's related to CPU and runaway processes in
the background. After installing a CPU monitor I can pretty easily see the
correlation between CPU usage and degradation in the touch recognition.

I'm not familiar with Android's architecture, but it seems like they need
better safeguards against runaway processes.

~~~
danellis
> I think it's related to CPU and runaway processes in the background.

I don't think it's that.

I got my Nexus 7 at Google I/O. The first one I got suffered from this same
issue right from the very beginning. I could barely even get past the welcome
screens, because I couldn't type certain letters on the keyboard. It was worst
at the bottom of the screen (which would be the right side in landscape as the
video points out).

The device help desk replaced it for me the next day. Unfortunately, the
second one had a different problem -- the display was badly corrupted, and the
left half of the screen (in portrait mode) was entirely red.

The third one seems to be working fine, apart from one annoying dead pixel.

~~~
ajross
I got my preorder tablet in the mail last night, and didn't see anything like
this over 4-5 hours of broad, "try everything" use. It might be an assembly or
component issue with early tablets. Both the linked article and the
grandparent seem to be arguing that it's heat related. Mine certainly got hot,
though the sample size is too low to make a determination.

~~~
27182818284
I'm with you. Got mine a few days ago and have noticed zero issues like this,
even while running games with the tablet flat on a bed.

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jan_g
If turning the screen off and back on rectifies the problem, then hopefully
this could be resolved with a patch.

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growt
The nexus one (or at least some) had a similar issue. After a while the
touchscreen became almost unusable. Turning the screen off and on again fixed
the issue, but it was annoying. Seemed like a hardware defect, because it
never got fixed by software. I hope this is not the same problem.

~~~
boh
I had the same problem with the Nexus S

~~~
sahaj
A similar thing happens to a Motorola Xoom that own. Turning the screen on and
off always fixes the issue. It's usually rare, once every month or so, so it's
not that annoying, but when it happens, I end up swiping multiple times and
then realize, oh I've run into that problem. I can live with it, but would be
nice if it was fixed.

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donniezazen
I have no problem what so ever with my Nexus. It's the most freaking awesome
tablet I have had.

Author and other people might have got a bad piece.

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de_dave
There's yet another similar issue with the Galaxy Nexus:
[http://code.google.com/p/android/issues/detail?can=2&sta...](http://code.google.com/p/android/issues/detail?can=2&start=0&num=100&q=&colspec=ID%20Type%20Status%20Owner%20Summary%20Stars&groupby=&sort=&id=23044)
(video included!)

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trimbo
So... I just let mine bake for 30 minutes on the same game he did. The device
was hot by the end of it. No problems with touch/multitouch recognition
afterwards.

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lnanek2
Had the same sort of problem with my Nexus One. Different OEM too. Pretty
strange. Maybe the open source version of Android doesn't have anyway to keep
the touch sensor calibrated beyond turning off and back on. I can recall
ThinkPad's where the trackpoint would get stuck going a certain direction
after some use as well. So continuously calibrating input devices is certainly
something that can be required.

~~~
idspispopd
If it's an overflow/waterfall type issue(for lack of a better descriptive
term) then turning the screen off and on will fix it temporarily until the
trigger (such as heat) sets it off again.

It's less likely a calibration issue because the rest of the screen is
performing accurately, and the behaviour is inconsistent.

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eevilspock
Seriously? From a single data point you deçide to cry wolf? I say this as an
iPad user.

~~~
simonh
Seriously? Given video proof, and without bothering to check for multiple
supporting testimony from other affected users, you make cheap irrelevant
accusations?

~~~
eevilspock
Sir, did you read the article? The author makes no mention of even anecdotal
evidence of problems beyond his single Nexus 7. You don't write an article
about a single defect instance. A post in a forum maybe, and _after_ there is
evidence of the problem being widespread you write an article. Perhaps I
should write an article about the rotten apple I bought yesterday and title it
"Whole Foods Apples Rotten".

The evidence that appears herein is _after the fact_ , and even so is hearsay
and subject to selection bias.

It's funny how well your comment applies to the article author, yet you attack
me.

~~~
aero142
I get the feeling that you only read the article and didn't watch the video
because in about the third sentence he says "There have, however, been some
sporadic reports of problems with the touch screen, and it turns out, the unit
that I have received does seem to be affected. So, I thought I would show you
what some of these problems look like."

He is obviously seeing other reports of problems and is presenting his own as
a representative instance.

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falcolas
Hmm. No such issue with mine. Might be a literal manufacturing defect.

I wonder if OP bothered to try and reproduce this with other models, or if
they decided to make a mountain out of a molehill.

~~~
huggyface
Have you used Tegra-specific software?

I grabbed SHADOWGUN THD (a Tegra-optimized game) this morning and experienced
exactly what the submitter experience: The game is very quickly completely
unplayable because you have to control movement on both sides of the screen,
which you quickly discover isn't possible.

I am a huge Android booster, but I have to confess to being quite disappointed
at this point. The screen has the left side defect where it raises from the
frame. There are bizarre lag glitches and pauses (start a Netflix movie and
for the first minute or so of play there are multi-second long video pauses).

I have a feeling this is going to turn into a giant PR disaster for
Google/Asus.

~~~
falcolas
Yes.

I wasn't willing to pay for Shadowgun just to test this, but I played Fruit
Ninja THD for a good 10 minutes with no problems. I also watched a full
Netflix show with no appreciable lag.

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guelo
I just tried his same test on my 7 with the same game and the same multitouch
tester app and I was unable to replicate the bug. Must be a manufacturing
issue that affects only some devices.

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mckoss
I've noted very bad screen flicker on the Nexus 7 when browsing the web (large
white background). This is a Google IO unit.

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huetsch
I've been skeptical of Google-branded hardware ever since my Nexus One stopped
working due to a non-functioning power button. I find myself associating
"beta" with their stuff - that's fine for software but not so much for
physical goods.

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thechut
I think this is most likely a software problem. There were similar problems
with multitouch in the bottom right corner of the Galaxy Nexus which was fixed
in the first OTA update, just a few weeks later.

~~~
idspispopd
If it's heat from the hardware, that can still be fixed with either more
optimised drivers, or outright capping performance.

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AshleysBrain
Any ideas if this is a software or hardware defect? If the former then a patch
may be on the way.

~~~
idspispopd
In most cases software or firmware patching is sufficient, even in the case of
some heat issues. If it can not be fixed via patch or only affecting a small
batch of users, then returns are a better approach to distributing firmware.

If it's widespread then google didn't do enough intervention testing(QA
processes). Which wouldn't be unusual since even mattel are guilty of letting
intervention testing slide. (It slows production and pushes up costs.)

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mgcross
FWIW, I just played Shadowgun for 20 minutes on my n7 and I'm not having any
touchscreen issues.

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momma-joe
i experienced this when I was registering, keyboard input would not register
until after 5-10 presses, then buffer filled up and spit it all out with
multiple key presses in the input box.

