Potential Nexus 7 Touch Screen Fix?
- Thread starter GSLEON3
- Start date
Well, I have waited for Google to try fixing my screen issues with software updates, I tried the other multi-touch fix in this section of the forum and finally gave in and tried your fix.
A fingernail and 5 minutes of my time last night have fixed my issue. Not a single touch issue in the last 24 hours. A huge thanks for this. :good:
Glad it worked. I have been meaning to get back to this with pictures & a better guide, but I bought an Amazon Kindle Fire HDX 8.9 & that has been keeping me very busy, what with getting GAPPS working & fixing half a dozen bricks a day. One of these days, lol... I get back to this & actually have an hour or two so that I can take some good pics showing the internal issues that lend themselves to exasperating the touch screen issues for some users.
I just did this. Will test it out over the next couple of days. I do have ts30 flashed though.
Here are some pictures and steps.
1) Start from the long sides of the device, work a fingernail into the edges and gently work it around towards the top and then to the other side. Remove it from top to bottom. You don't want to force it because the back cover kind of slips behind the USB port and you might crack it.
2) This is the part the OP was talking about. If it's loose for you (it wasn't for me) you can go ahead and reconnect it. As it wasn't loose for me, I used a plastic knife and popped it off without remove the tape and simply pushed it back in.
Tried that too several times.
After a few hours of use - or around 1 day of standby - the touchscreen problems are back.
Which problems? (there are many different touch problems: multi touch, freezing, ghost touches, etc. )
Well my nexus stopped responding to touch for a few seconds. Once this problem started I could only remove it by restarting my device. Today I noticed one touch being registered in the wrong place. It didn't happen again, so I got that going for me, which is nice.
This is the exact problem I just started having after a couple weeks of use. I don't think this is strictly a hardware issue. Today when it started doing this, I was laying on my bed typing and it slowed down to a crawl. It was accepting one out of every 3 or four key presses. If I touched for more than a couple of seconds, it would finally register, usually acting immediately as if it were a long press. At first I thought it might be related to Google Keyboard. I changed to a couple others with no change. In fact, the behavior was consistent throughout the GUI. And once this happened, it stayed the same - I put it on the bed, I held it in both hands, I squeezed it, I stood up on the carpet, I stood on the hardwood floor, I put it on the counter, I touched my elbow to my FiOS box and then to the light switch to make sure I was grounded, and I sat on the toilet. Nothing fixed it, EXCEPT plugging it into the charger. The symptoms disappeared immediately. What surprised me is that when I unplugged it, the symptoms returned immediately. I wanted to take advantage of having it in this state, to try to find out SOMETHING concrete - this is driving me nuts. I turned on some debugging options like CPU monitoring and some GPU options, turned off all Background processes, and set it to "Don't keep activities" to ON. Still no change at all. The experimenting went on intermittently for about 2 hours without a change in behavior. I was at least able to nail the exact behavior down to it taking two to three seconds to initially respond to a touch. If I left my finger on the screen I could draw like a madman and color in the entire screen without missing a pixel.
I opened the Nexus 7 II Screen Test App from Google play - the one that displays different test patterns, (https://play.google.com/store/apps/details?id=com.gombosdev.nexus7tester) some of which invoke ghost touches, app switching, and other weird stuff. (it requires no special privileges, so I'm 99% sure it's legit) I picked a couple of patterns that didn't affect the screen, then I picked (I think) pattern 1 and the screen went bonkers (in a somewhat predictable way even though it looks random). I could see ghost presses really fast on the software buttons, Google Now opened, it went back to the desktop, back to the app, and then FC. I opened the app again, selected the same pattern and the exact same thing happened.
After that I didn't re-open the Screen Test App, but went back to Chrome. The tablet was suddenly ultra responsive. I mean snappy - no problem at all. I am absolutely certain that the app I'm talking about was not running prior to that - in fact nothing was since I had turned off background processes. I turned off all debug options so processes could run again. Still, the tablet is absolutely screaming right now and it's been about 4 hours since then.
Unless there was some extraordinary coincidence, the screen test app "crashing" this display (not sure what else to call it) completely resolved the problem at least for now. Plugging it in had solved the problem while it was plugged in, but whatever happened when that app displayed the test pattern that made the screen tank, caused it to start working properly again. Because none of it is very logical, this is the first time I had some time to actually test various things without rushing to try to get it working and then not knowing what fixed it. Since I can't make it start acting funky, I'll have to wait until the next time it starts doing this to see if I can reproduce it.
This seems weird enough to be consistent with people opening up the tablet looking at the cable, closing it, and then it suddenly works. It's tough to nail down if it was opening it, touching the cable, re-seating the cable, closing it, etc that made it work. This time, I'm certain that it started to work immediately after the screen displayed from the test app caused it to freak out. Not quite enough to establish cause and effect, but it's closer than I've been so far. Any thoughts?
It might be an app that does this. After I play "Doodle Army" for a while, the controls become unresponsive. After exiting the game, YAMTT shows that my screen now has dead spots and won't register multiple touches properly. Yet everything's fine after a reboot.
Thanks GSLEON3 ! I had issues with touches not recognised on occasions. Some apps seem to be more responsive than others and so I chalked it up to the OS software issue category.
Now after taking the back off and looking at the cable.....it seemed to be plugged in all the way into the socket. So I just unplugged it with some tweasers as to not lift the sticker off.....then pushed the cable back into the socket.
Booted the N7 back up and now the touch response is vastly better !! Not sure if reestablishing the socket connection at the end of the ribbon cable caused some sort of reconnection sense with the digitizer...but it definitely works better now. And I did not have a big problem like many.....only slight non response touches on occasions. Now the touches seem very quick and snappy.
:good:
Now after taking the back off and looking at the cable.....it seemed to be plugged in all the way into the socket. So I just unplugged it with some tweasers as to not lift the sticker off.....then pushed the cable back into the socket.
Booted the N7 back up and now the touch response is vastly better !! Not sure if reestablishing the socket connection at the end of the ribbon cable caused some sort of reconnection sense with the digitizer...but it definitely works better now. And I did not have a big problem like many.....only slight non response touches on occasions. Now the touches seem very quick and snappy.
:good:
Can you please check back in and let us know if the fix seems to last for a while or if the problems return?
Sent from my Nexus 7 using Tapatalk
No, never even when it works "right".
This fixes mine temporarily, but after some time problems are back. I just open and replug, maybe putting something to keep the pressure... But don't know what or how to stick somthing in there without messing.
Any ideas?
EtherealRemnant
Senior Member
I've found that the only time I have touchscreen problems is when I have it in something other than my hands. If I put it in a case, it messes up. If its lying on the couch, it messes up.
I've even figured out that if I need one hand free, I just place my thumb around the edge and I can tap anywhere on the screen without issue.
Its the strangest thing. I've never seen anything like it. I downloaded a multitouch test just to see and sure enough, if its in my case, on the table, or on the floor, it jumps around and sometimes doesn't register at all. If its on my leg on my jeans, it conducts. It also does on my shirt.
I don't get it at all but it works so I don't worry about it.
I've even figured out that if I need one hand free, I just place my thumb around the edge and I can tap anywhere on the screen without issue.
Its the strangest thing. I've never seen anything like it. I downloaded a multitouch test just to see and sure enough, if its in my case, on the table, or on the floor, it jumps around and sometimes doesn't register at all. If its on my leg on my jeans, it conducts. It also does on my shirt.
I don't get it at all but it works so I don't worry about it.
Seems you might have one of the early batches made. This was an issue when the tablet was first released. I took back my first one because of it. The last one I got did not have this issue. Try plugging into the charger when on and using it without holding in your hands, that was how I quickly determined this issues when I first got it.
I would see about getting a full replacement if you can, but sending back on warranty would be a last case for you there.
---------- Post added at 10:45 AM ---------- Previous post was at 10:44 AM ----------
Sure, I use my N7 daily, so after a week or several...I will report back if I notice any change.
Thank you. I am not currently having the issue, but I was and I really haven't done anything to fix it. It seems to be a tough issue to nail down, and the more info we have based on real world results, the better.
Mike
Sent from my Nexus 7 using Tapatalk
Ok now after using my N7 2013 for 4 days after doing the screen cable reconnection process......tablet is still consistently working extremely well in regards to touch sensing. Even with the SPG Ultra Clear protector on.....it registers touches with just slight physical contact and very quickly. Definitely much snappier than before and not sure it could get any quicker in response. I tested with over 12 apps and various areas in the launcher UI. Charged up 3 times and powered on/off several times as well.
I hope it was just some minor flaw of the ribbon contact ends or socket needing some slight abrasion to get a solid connection established. I wonder if some sort of finish element on the contact points needed to be "scratched/worn/rubbed" to allow 100% connectivity with 0 degree loss. Just a theory.
Needless to say......wow I wish I would of done this long ago when I first heard about it. You have nothing to loose if you carefully get the back cover off and reconnect the ribbon cable end. I did have a tricky time at first getting the back cover off around the power button upper corner area. It was not separating as easily as the opposite side and top edge near the camera area. I just worked it slowly and was also careful of taking the cover off around the power plug connector on the bottom lastly.
Good luck to those that have touch problems.....hope this is also a fix for you.
I hope it was just some minor flaw of the ribbon contact ends or socket needing some slight abrasion to get a solid connection established. I wonder if some sort of finish element on the contact points needed to be "scratched/worn/rubbed" to allow 100% connectivity with 0 degree loss. Just a theory.
Needless to say......wow I wish I would of done this long ago when I first heard about it. You have nothing to loose if you carefully get the back cover off and reconnect the ribbon cable end. I did have a tricky time at first getting the back cover off around the power button upper corner area. It was not separating as easily as the opposite side and top edge near the camera area. I just worked it slowly and was also careful of taking the cover off around the power plug connector on the bottom lastly.
Good luck to those that have touch problems.....hope this is also a fix for you.
dont work for me
Hi everyone, I just did this but after closing back I test it in YAMTT with same result: top half of screen not registering touches. In hands or in charger it is ok. With headphones it is ok also. And it is worst alter playing games (when the tablet is heat).
I unplug and plug the ribbon cable without loosing tape..
Any suggestions?
Thanks
---- EDIT:
I opened it again today. I reconnect battery (i didnt do a battery reconnect yesterday) and that ribbon cable again... After hour of playing Real Racing 3 tablet is heat and touchscreen works perfect! But maybe it's just coincidence. I hope it is solved. I will post there about progress of this..
MK
Hi everyone, I just did this but after closing back I test it in YAMTT with same result: top half of screen not registering touches. In hands or in charger it is ok. With headphones it is ok also. And it is worst alter playing games (when the tablet is heat).
I unplug and plug the ribbon cable without loosing tape..
Any suggestions?
Thanks
---- EDIT:
I opened it again today. I reconnect battery (i didnt do a battery reconnect yesterday) and that ribbon cable again... After hour of playing Real Racing 3 tablet is heat and touchscreen works perfect! But maybe it's just coincidence. I hope it is solved. I will post there about progress of this..
MK
Last edited:
Similar threads
Top Liked Posts
-
There are no posts matching your filters.
-
49I just wanted to report on a possible fix to touchscreen issues. While this may, or may not, work for you, it is what I did, what I have done on three(3) total devices & it is what has eliminated touch screen issues for myself & two other individuals.
This is a work in progress & I will be adding pictures & more detailed instructions, along with progress updates as I use the device going forward. This modification (though it really isn't a mod) requires no tools & while it does entail some light dis-assembly, it did NOT require breaking any seals that would void the warranty outright. Doing this however, may very well void your warranty, I am not an attorney, I am an engineer & taking things apart is what I have been doing since before I could even crawl nearly forty years ago.
To begin, I will go into my Nexus 7 story, which may allow you to identify similar symptoms.
My Nexus 7 device worked well out of the box, with only occasional multi-touch issues. As time progressed, the issues got worse & at one point a couple of weeks ago, even single touch event started to lag or not register. My Nexus 7 is a batch from July of 2013 & I purchased it in August of 2013, so it was still under warranty. Asus issued me an RMA number, however, I hate broken things, knowing darn well that 99% of the time I can fix them myself far faster than the total time it would take an OEM to get my device back to me. At any rate, after the 4.4 update, my touch issues got even worse. Aside from missing even simple gestures & taps, occasionally the screen would look funny & once it even had a sttatic "snowy" screen that was remedied by a factory reset.
After reading a few complaints from people about screen separation & investigating the device via the ifixit tear down, I decided I would take a look before committing to the RMA process. I gently slid my thumbnail under the bezel & slowly worked it around. Immediately I could feel the clips giving way & I eventually had the back cover off. Once the back cover is off, you will notice that the screen & digitizer ribbon cable runs across the battery, pinned in between the battery tray & the inductive Qi coil on the back cover of the device. I found it is easier to ease all the sides up slightly, then remove the back by gently lifing from the sides & upper portion, with the bottom, where the USB port is, being lifted up last. Once I removed the cover, I disconnected the battery terminal clip. After disconnecting the battery, I then followed the screen ribbon cable to where it is clipped into the screens board contacts with a plastic stay. Immediately upon applying pressure to the cable ribbon stay I felt & heard a faintly audible "click" sound. On closer inspection, I discovered that poor contact was being made by the ribbon cable & furthermore, the flex in the battery tray over time, when coupled with the heat generated at that location (due to the battery & the inductive Qi coil) can slowly loosen the ribbon cable stay & affect the quality of the connection. I used a thin piece of composite material to reinforce the cable ribbon stay & used a piece of vinyl along with a non-conductive adhesive to better secure the cable ribbon & stay. I only used a tiny amount so as not to affect the ability to safely disconnect the ribbon cable without destroying it. I also did not want a bunch of adhesive heating up & spreading to other areas. Before I performed the following step, I decided to test out a few thoughts. What I discovered is detailed in the next paragraph. So, after letting the adhesive dry overnight, I reattached the battery terminal clip & started the device. It has worked flawlessly since, without any touch issues.
While I had the back cover off, I carefully reattached the battery terminal clip & while wearing Nitrile gloves & standing on a wood floor to minimize the risk of static discharge, I would turn the device on with the display ribbon cable in various states of connection. They ranged from being angled so that the far contacts would make little or limited connection, to a full connection with varying degrees of pressure applied, to simulate a good or bad connection. Sometimes the device would not boot. Other times it would boot & have a static or "snowy" screen. Sometimes it affected all touch, from single finger events to multi-touch. It also surprisingly affected the system response. Things would freeze up & apps would FC or ANR. Again, once I improved the connection, everything was back to normal & functioning perfectly. In fact, it is functioning better than it did out of the box.
While I am sure Asus would argue that this voids the warranty, I did not break any seals. No tools were needed, just the materials I chose to use & had lying around. As I also mentioned in the opening, I did this on another household members device, that only had multi-touch issues, not all the issues I had, & their device has now been functioning wonderfully for the last several days. The display ribbon clip in their device was not completely detached on one side like mine, but it was fairly loose all the same. The third device was a friends & it was having mostly single touch issues, though he said multi-touch issues would come & go. We ran through the steps on Hangouts & his ribbon cable was in its place, but as he removed the back, the stay clip fell out. His device is also functioning normally now & he has not reported any further touch screen issues.
Since the problems people are having are oftentimes different & not consistent, it very well could be that this is exactly the issue. I would surmise that it could be the very reason why Google & Asus have been VERY, VERY quiet about the issue, since it would require returning the device for a fix, not simply a software fix.
If you try this, I urge you to be patient & use the utmost care when removing the back. While there are no cable attached to the back, you never want to force things. Be gentle & when you find the right spot for lifting, you will know it. It is not difficult & it is relatively harmless. I would caution you to use gloves & minimize the risk of discharging static electricity. I also recommend using gloves because copper sheeting is used in a couple spots & if you have ever worked with copper sheeting in electronics, you know that stuff grabs oils from your skin like crazy & you will end up leaving evidence in the form of an ultra-clear fingerprint that almost no solvent will remove. (Don't use solvents in your device unless you are a daredevil or know what you are doing).
So, that is my story & what worked for me & my small group. Ultimately, these devices are ours & it is up to each of us individually to pursue the fixes or mods that suit us best. That also means that the responsibility & consequences belong to each of us as individuals. What steps you are willing take to remedy any issues you may have with your device are decisions you need to weigh. This is XDA, where people take risks, assume that the are eventually going to brick their devices & make real modifications to devices (which this really is not). If you break something because you needed every single little detail & step spelled out for you, that's not my problem. Again, this is XDA, not some ragtime blog & anything you do here usually requires you to be able to think for yourself at some point.
Lastly, I will try to get to a step by step with pictures as soon as I can. I am not a developer, I am not a student & I don't have a ton of time to devote to answering questions. I will do what I can, when I can, but between the holidays & my job as a mechanical engineer (two large hospital projects are going on right now that take up 95% of my day), I have very little time right now. This post is the result of a large lunch review meeting, not free time, so it will probably take some time to get everything up. I have to recreate most of it, since I really figured on RMA'ing my device. I never expected this to work as it has for me.
Thanks.9
Our touchscreen has also a rough calibrate as they are calling it. I don't know if it runs timely by the firmware.
But you can force it with "echo ff > /proc/ektf_dbg"
If done correctly, in the kernel msg log you will find
[ektf3k]:[elan] dump cmd: 54, 29, 00, 01
[ektf3k]:Run command: 0x000000FF result:0
EDIT:
Also you can check your fw version by "cat /sys/devices/i2c-3/3-0010/vendor"
Modified fw will show a version bigger than _A044 to disable flashing of newer one.
Actually Nexus 7 2013 probably doesn't have different touchscreen revisions. Well, anyway, drivers and fw can't distinguish them for sure.
The different firmwares are obtainable by the kernel source. They are basically bugfixing versions. Like let's say android 4.4.1 to 4.4.2.
The problem in our tablets arise firstly from the totally crap ESD (electostatic discharge) protection mechanisms and the huge EMIs (Electromagnetic interference) produced by mainly our LCD's WLED back light driver and also other power components.
You can learn more if you search for touchscreen ESD protection and EMI.
So in most cases in these forums (hovering, ghost touches, unintentional releases, etc ), the problem comes from EMI produced by the things I said above.
So when the interference is strong, when we touch the screen it starts behaving very bad.
Why only when you touch it though? Our devices, have a problem in noise radiating from our fingers. So our body catches the radiated noise from the backlight driver (mainly), fluorescent lamps, charger, or whatever is lower than 1MHz and transmits it to the touchscreen.
This is way problematic because this is the frequency range that touchpanels work. But ours have a crap algorithm and shielding that can't cope with it.
What you can do? 2 things as many said before:
- Minimize EMI by covering and protecting touscreen components and EMI radiating power components inside the tablet.
- Trying different firmware versions.
Let's see option 2:
All and I mean ALL touchscreen manufacturers have ESD protection algorithms in software/firmware.
Some/Most have also hardware design and mechanisms/shields for ESD protection.
So for all this noise that I said before, the solution is by using frequency hopping and heavy algorithms that identify and eliminate this ghost touches.
So if you checked the fw versions, you will see that they tried/fixed/introduced such mechanisms. Let's check some and take a guess on why:
- Improve "under table lamp" performance. //Probably because of EMI from the electronic transformer of a Halogen table lamp
- Modify Open/Short Calibration Mechanism for ESD problem //And others for calibration ESD mechanisms, fix for timely(?) calibrations to identify EMI
- Fix the Sensitivity Problem That Suspend and Wake up When Charging //They have different protections for EMI based on power source and drainage, like battery, AC charger and slimport hdmi (huge EMI coming from TV).
- Noise problem. // That's clear
- Add ESD Protection Mechanism //Aha
And well many others that are disguised but are problems coming from EMI noise.
As you see, they try and try and try(some fw have the same bug issue 2 times, that means a fail in previous fix) but the problem is there.
Why? Elan tech has the worst touchscreens and also ASUS was stupid not to check the behavior between the LCD and ELAN tech touchscreen. Ask people with laptops that have ELANtech touchpads. I don't know any of them, that they don't disabled it completely and use a mouse.
So why these firmwares have different results to different nexus 7 2013s?
Because of different algorithms and different calibrations. Also the devices have differences in build (humans assembly them) so different EMI patterns. It seems that A011 (if this is what sfhub calls as a ts-10) has the most heavy heuristic algorithm and the biggest SNR.
So yeah if you have (sporadic) problems that don't fall in extreme cases (non-sporadic or long occurrence), a specific fw may fix it for you.8I just did this. Will test it out over the next couple of days. I do have ts30 flashed though.
Here are some pictures and steps.
1) Start from the long sides of the device, work a fingernail into the edges and gently work it around towards the top and then to the other side. Remove it from top to bottom. You don't want to force it because the back cover kind of slips behind the USB port and you might crack it.
2) This is the part the OP was talking about. If it's loose for you (it wasn't for me) you can go ahead and reconnect it. As it wasn't loose for me, I used a plastic knife and popped it off without remove the tape and simply pushed it back in.
6Just finished this 10 minute little fix that, so far, has completely fixed all of the touch issues for me. I can actually use the device when I'm not holding it now!!!
So I just wanted to say thank you very, very much for this post. I highly recommend this quick easy, and very simple fix to ANYONE having touch issues. Its so easy, no tools required, just pop off the back, and simply push down on the golden/orange ribbon at where the top of the device would be. Just make sure the connector there is completely flat. Or you can simply pop up the connector and reconnect to get that nice, confirming click sound and satisfaction knowing your touch issues are completely resolved now! ????
Seriously, thank you again for trying this on your device, confirming and writing this post for the rest of us. It is greatly appreciated, and I think this should be labeled as "the" fix for any and all touchscreen issues, because no software update/fix can cure a loose connection, for those that have this issue.
The touch issue was the one thing that kept me from completely loving this device, and now everything is perfect- for me anyway, as it should be!!
Thank you!
Happy Turkey day
Sent from my Nexus 7 using Tapatalk 45Video might be tough, but I'll try to get to it. I will try to dedicate some time this weekend. I was thinking Saturday night, but I just learned that the Day of the Doctor is being simulcast in 3D near my house. So it may have to wait till Sunday so I can let my inner geek out.
Sent from my Nexus 7 using XDA Premium HD app
