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[Q] Center touchscreen unresponsive - Can't type

My nexus s at times tends to be unresponsive at the center part of the screen. This problem has actually plague me from since I was in stock 2.3.1 and followed on up to now. From my searches, I know I'm not the only one that has this problem and some speculate that having a screen protector contributes to this problem.
My best bet is that this would be more of a software problem than a hardware side as a quick lock/unlock always fixes this issue. Below is a request by someone in cyanogenmod and I find that his response seems to have some good basis. I was hoping with a better background in developing this stuff could help. Also what to know who else out there is experiencing the same problem.
Recently I've got a Nexus S, and I fount its touchscreen sometimes unresponsive, especially right after unlock. The center of the screen cannot sense tapping, but the edge and corner area works well. The four soft keys always works great, but I think they are controlled by a different cypress chip. I've tried to connect adb and "cat /dev/input/event0" and the result confirms my observation. Searching a Chinese android-lover forum, I found several guys are experiencing similar problem. (Some are running stock, others, including me runs CM-7rc). The problem can be strangely solved by locking and unlocking the phone quickly, and when the touchscreen is working correctly, it's actually very sensitive and responsive.
Suspecting a driver issue, I looked into the source of touchscreen controller (AMTEL MXT224) driver (/driver/input/mxt224.c) by Samsung and compared it to drivers of the same chip by Motorola and HTC. I notice that HTC and Moto's drivers send calibrate signals to the touchscreen controller in there resume method, but samsung's does not. I doubt whether it's the cause of issue. Modifying driver and compiling android kernel are beyond my knowledge, so I'm calling for help.
I know not all nexus s are suffering this, so I'm read to test and provide feedback. Any help would be greatly appreciated!
HTC driver (http://pastebin.com/7BZvp50x, http://pastebin.com/wxMV9ifY)
Moto driver (http://pastebin.com/5jnT8jvv, http://pastebin.com/yNH3nUa5)
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Keyboard registering multiple taps

Not totally sure how to describe this, but my Optimus 3D seems to be registering a single tap on the on-screen keyboard as multiple presses, usually 2-3. Has anyone else experienced this issue? Is it more of an android issue rather than with the phone? Or could it possibly be resolved through the installation of an alternative keyboard from the market?
The issue seems to occur both when charging and when running on battery power, and occurs in all applications I've tried it in so far. (Browser, Market, YouTube, Messaging)
I'm just concerned there could be an issue with the screen, so I'd like to try and get it sorted sooner rather than later, since once you go past a week or two getting a faulty phone handset sorted becomes a nightmare with retailers.

Lagamorph said:
Not totally sure how to describe this, but my Optimus 3D seems to be registering a single tap on the on-screen keyboard as multiple presses, usually 2-3. Has anyone else experienced this issue? Is it more of an android issue rather than with the phone? Or could it possibly be resolved through the installation of an alternative keyboard from the market?
The issue seems to occur both when charging and when running on battery power, and occurs in all applications I've tried it in so far. (Browser, Market, YouTube, Messaging)
I'm just concerned there could be an issue with the screen, so I'd like to try and get it sorted sooner rather than later, since once you go past a week or two getting a faulty phone handset sorted becomes a nightmare with retailers.
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The screen of the phone is very very sensitive. What happens is that you touch the letter and then before you have the time to remove it the phone registers a continuing press. This happens because even if you dont tap with the same presure, the phone still picks up a presure and registers more taps. It isn't really something you should worry about.

Ahhh I see. Is there a way to reduce the sensitivity at all? It's a rather annoying bug and makes it next to impossible to type anything longer than just a few words using the on-screen keyboard.

Lagamorph said:
Not totally sure how to describe this, but my Optimus 3D seems to be registering a single tap on the on-screen keyboard as multiple presses, usually 2-3. Has anyone else experienced this issue? Is it more of an android issue rather than with the phone? Or could it possibly be resolved through the installation of an alternative keyboard from the market?
The issue seems to occur both when charging and when running on battery power, and occurs in all applications I've tried it in so far. (Browser, Market, YouTube, Messaging)
I'm just concerned there could be an issue with the screen, so I'd like to try and get it sorted sooner rather than later, since once you go past a week or two getting a faulty phone handset sorted becomes a nightmare with retailers.
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Click to collapse
I would recommend you to compare your phone with another O3D if you can. If some other O3D's work nice for you, then probably it is a harware defect.
I have never experienced such a problem on mine.

Hm, I don't know anybody else with one, however the store I bought it from did have a demonstration unit so I can pop in and try out theirs to see if it also has the same issue. If not at least I can demonstrate the problem to them.

Lagamorph said:
Hm, I don't know anybody else with one, however the store I bought it from did have a demonstration unit so I can pop in and try out theirs to see if it also has the same issue. If not at least I can demonstrate the problem to them.
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Sounds like a plan to me

I had the same problem as the OP.
It was not from the beginning and started totally unexpected and there was a very noticeable difference before/after. Typing became almost impossible, had to do it veeery carefully.
However, a simple reboot solved my problem. Didn't happen to me again since...

Hi, totally new to Android after being with Apple a long time but loving my O3D except battery life but i'll live with that.
Does have a few niggles but it makes my iphone look sooo out dated!
Right, i have similar issue with letters duplicating but it only happens every now and then and is cured by restarting the phone.
Looks like a software glitch because typing on this phone is as good as when i use my iphone. I'm more than happy with the sensitivity.

I never thought of restarting the phone, but I've done it now and it seems to have fixed the problem. Now I just need to get used to the bigger screen then my crappy old iphone.

I love the screen size in general, though I downloaded a pinball game that only works in portrait which is not really playable because the phone is too heavy to hold only with the bottom.
Its certainly a lot easier to type than I expected coming from the N900. I really REALLY wanted something like the Optimus 3D but with a real keyboard, but sadly I can't see it happening. This "thinner is better" fad really winds me up, I prefer function over form any day of the week.
Speaking of typing, I certainly have had the key repeat problem - I thought it was a build up of grease on the touch screen confusing it. It was quite annoying as my first impression was that typing on this thing is almost as good as a hardware keyboard, then the key repeat issue surfaced. Lets see if firmware 10d fixes it.

update to HTC_IME and u wont have such problem anymore. I had same issue with standart LG keyboard

I'm having the same problem with my keyboard.
It started recently and it's very annoying to try to write a txt with a such sensitive response from the keyboard.
Restating the phone seems to have sorted the problem but, it's weird...

i had this same problem after using the phone perfectly for 2 weeks it suddenly started this annoying habit,i took it back to the carphone warehouse and they exchanged it,so far the replacement is fine.

[Q] touchScreen not working

Bought a nearly new galaxy tab2 from the internet, but the touchscreen seems not to be working.
Any idea what that can be. Could it be something with a ROM, or does it need to go to Samsung.

OOge said:
Bought a nearly new galaxy tab2 from the internet, but the touchscreen seems not to be working.
Any idea what that can be. Could it be something with a ROM, or does it need to go to Samsung.
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It could be failed hardware, a bad cable, or perhaps a problem with the touchscreen controller chip.
If you can capture the boot messages using 'dmesg' over ADB, there may be info there that could help determine which.

If it's under warranty, return it to the seller for a refund or replacement, else just keep searching for a solution :\

OOge said:
Bought a nearly new galaxy tab2 from the internet, but the touchscreen seems not to be working.
Any idea what that can be. Could it be something with a ROM, or does it need to go to Samsung.
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When you say the touchscreen "seems" to not be working, what exactly do you mean?
Does it not work AT ALL, or is it just not very responsive to your touch, i.e. scrolling is slow and choppy and/or pinch to zoom is flaky?
Because I have noticed certain apps do not work well on my 10.1 when it comes to the touchscreen, when the tablet is under heavy load. Are you experiencing this more with certain apps, like Chrome and/or Samsung Keyboard? If that's what is happening, I can help.

I use a custom firmware, so not possible to return to samsung.
As it is stuck on the install screen, I can't enable debug for ADB.
Or is it auto enabled on a custom rom.
What has the highest chance of failing. Logic board or digitizer (as the cable is not sold seperatly)

I have a Tab 2 P5110, I bought it as faulty as the touchscreen is not working. Otherwise it's alive and responding to the buttons.
After reading several topics it looks like it is a bug that can only be fixed by physically replacing the digitizer panel.
Of course I'd prefer a software solution but so far what I've found wouldn't work on this model due to HW difference.
Can someone confirm that?
Thanks.

[Q] Touchscreen problem: "Phantom" touches

There are lots of videos showing this problem: after you have touched the screen sometimes the screen registers finger presses even after you've removed them.
It's very hard to see what is going on if you don't turn on "show touches" in settings, so I suspect many reports about touch screens being unresponsive, or acting strangely is really the same problem.
It occurs both in stock ROMs and aosp, but subjectively more often in stock roms. It's not about moisture remaining, I've wiped the screen completely clean and dry and the phantom touches are there before, during and after cleaning.
Is there a software solution to this or is it hardware? Any thoughts of how this problem could be approached? I'm having trouble even reproducing it reliably.

yet another video of the odd problem: https://www.dropbox.com/s/mglol5qon6vy67g/2013-08-11 20.15.01.mp4

I replaced my Asus TF300 because of a similar issue. Asus fixed it once under warranty (replaced the entire LCD and digitizer, I think) but the issue came right back within a few months after RMA. By then the warranty had expired. In my case, the ghost touches were prevalent in a specific part of the screen; couldn't tell from your video whether the false touches were in the same general area every time or not.
Surprisingly, until the problem became so bad that an entire area was unusable, I could flash a new ROM and get somewhat different behavior. Just to be sure, though, I did flash a stock ROM prior to sending back to Asus and verified the issue existed there, labeled the area with tape so they could not miss it, and described in details the steps to reproduce.
Good luck.
Sent from my GT-N8013 using xda app-developers app

bsaman said:
I
Surprisingly, until the problem became so bad that an entire area was unusable, I could flash a new ROM and get somewhat different behavior.
Sent from my GT-N8013 using xda app-developers app
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This is my experience also, the aosp revolt rom, seems to suffer much less so than the stock roms.
It does seem to be the same area but it might be just because it's the side that is used most often for scrolling due to me being right handed.
The difference between how the roms behave is what make me suspect it's a software issue.
Just to be clear, you've not noticed this even once with your note? Before I turned on the "show touches" I saw it most clearly when I used chrome or other programs with scrollable elements. The page would sometimes just vibrate a little when left alone.

PremiumMediocre said:
Just to be clear, you've not noticed this even once with your note? Before I turned on the "show touches" I saw it most clearly when I used chrome or other programs with scrollable elements. The page would sometimes just vibrate a little when left alone.
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No, my note has been rock solid, but I haven't enabled show touches so I can't say for sure.
Sent from my Vivid 4G using xda app-developers app

I'm thinking it might be possible to alter the idc file that specifies the behaviour of the touchscreen (https://source.android.com/devices/tech/input/input-device-configuration-files.html). But it's all a bit over my head.
I'm not alone at least:
http://www.youtube.com/watch?v=ii7m2696T3Y

A simpler cause?
I'm not alone at least:
(YouTube Video URL that I'm not allowed to post, yet)
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The guy in the video did a great job with research. Did you catch the part where he found nearly imperceptible damage to the screen that was a possible cause? The ghosting always seems to occur in the same places because that's where the screen has been "crushed". Now "crushed" is a bad word because the screen probably hasn't been compressed beyond an acceptable level but there might be some correlation between where the users normally places his/her hand when using the pen and where the phantom touches occur. Maybe when writing, some users are baring-down harder than they realize and prolonged pressure in the same arc-shaped area created by the side of a hand, causes some changes in the capacitive properties in that area which cause a "latch" condition -- where the digitizer gets stuck and won't unstick until power is removed.
I've noticed in the videos that I've seen that the presenter get the problem to appear when using the side of their hand in a rolling fashion -- probably the same motion that they use when they just start to write. I also believe that devices that have this problem "get better" or less sensitive when not used for a while. This would follow the idea that the screen is compressed and given some time, the compression relaxes.
If the problem is limited to a certain area of the screen, I find it hard to believe that the problem could possibly have anything to do with ROM or firmware. The matrix of the digitizer in X-Y coordinates is addressed such that if there were a problem like this, the error would occur and repeat in either a straight vertical or horizontal direction instead of finite points spanning many rows and columns.
I guess one way of ruling this idea out would be to find someone who has never used the pen to write yet still has the problem.

I haven't ruled out that it is hardware related, but I have noted a significant improvement leaving stock ROMs for aosp. Maybe that's just a coincidence, I can't know for sure. I have noted something else that might help diagnose this problem.
If the period of turning on the screen, using the tablet then turning off the screen constitutes one session, there are two types of sessions. Sessions which suffer from this problem, which will be apparent in a relative short period of time. But there are also sessions where everything works as it should, regardless of how long the session is. So you will notice this problem within 10 min or not at all.

[Help] Weird Issue with touchscreen/digitizer on MTCD PX5 Xtrons unit

Hi everyone!
I've been using an Xtrons TE103ap which is basically a MTCD/E PX5 unit. It operates off of a swivel 10.1 inch screen.
I've been having intermittent issues over the last 1 year where the screen would be unresponsive when the swivel is set to certain angles, so I assumed it was an issue with the connection. It runs off a generic 40 pin ribbon (the kind you find off floppy drives). I replaced it with a new cable and the problem went away for a while.
Every now and then, it would be unresponsive to touch requiring a complete reboot to get working again.
As of 3 days ago, the touch response started becoming laggy, ie. after touching a certain point, it would take about 1 second to respond. No amount of jiggling or wire switching fixed the issue.
I have done a complete teardown of the screen module and i've noticed that the digitizer ribbon is separate from the touch panel's ribbon. All contact points seem to be working and it doesn't seem to be a cable issue.
Assuming it were a digitizer issue, the touch panel's controls would still work right?
The last 3 days, i've been trying everything from going from Android 8 to Android 10, no fortune. I did try several MCU's and one particular MCU got the screen working for a while, long enough for me to get into factory settings and do a configuration. On reboot, i lost all touch functions again...
As of now, i'm perplexed as to whether it is a hardware issue or possibly software issue. Hoping anyone could shed some light.
Thanks !