Screen Sensitivity Issue Status in Cyan (1520)

[tor landeel]

I can confirm that bending, given the randomness of the phantom taps, does not work at all.
On the other hand, I disabled GLANCE, and set sensitivity to NORMAL. Nothing else, and the phone looks like another world.
I was terrified by swipes, no more taps at the moment (just a couple in a few hours of heavy testing, within tolerance considering I have a film on the display).
I will go on testing...since I'm able to return it within a month, I will stress test it and make up my mind, to keep it or go back to the 930.

 

[sklchan]

I can confirm that bending, given the randomness of the phantom taps, does not work at all.
On the other hand, I disabled GLANCE, and set sensitivity to NORMAL. Nothing else, and the phone looks like another world.
I was terrified by swipes, no more taps at the moment (just a couple in a few hours of heavy testing, within tolerance considering I have a film on the display).
I will go on testing...since I'm able to return it within a month, I will stress test it and make up my mind, to keep it or go back to the 930.

I've both items that you set in active and high sensitivity but no phantom taps here after the bending, and it remain more than months now all still good...

 

[slysy]

Thanks Hesham but I didn't fully understand your post. Could you maybe draw some arrows or circles in the pictures to show what we are meant to be looking at please?

 

[Hesham Fouad]

Thanks Slysy, the phone internal part is top quality like like al Nokia phones, how ever this is the first windows large screen phone, comparing to android they have more than 8 years experience in phone operating system, even with android when a stuck process in CPU it freezes the phone produce some false tap , since Microsoft didn't reply we have to wait for more advanced development in windows phone system, they are getting better but very slow never have or want the lead

 

[l1520orAFK]

Has anyone tried to bring to a Nokia care center directly? Did they try to change the screen/digitizer? Did it work? The bending fix attenuates the problem but it doesn't go away. I had my screen replaced a while ago for another screen blemish unrelated but the issue remains the same.

 

[Hesham Fouad]

Like I said its more related to software certain process stuck on CPU causing it to slow down , that's why when you fresh restart your phone problem disappear we will have to wait till Microsoft get more experience in mobile software development
It's remind me by windows 95 when ever any application freeze it affect the whole system, consider this bug a blue screen for windows phone

 

[l1520orAFK]

So hesham, you're saying this touch bug is most likely caused by CPU issues/throttles? This isn't a hardware design fault (I am not counting CPU problems as hardware)

 

[Hesham Fouad]

Yes from my point of view, I do this as a test, close all application and get back to main live tile, press back button 3 more times to make sure nothing running in background now open your most false tab app and test it , it should work smoother,
I keep glance on ,touch high, but double tab off, cause it consume battery and sunlight readability off cause it work when am inside room and not very accurate.

 

[Hesham Fouad]

I'm doing some last testing wish me luck

 

[Hesham Fouad]

Ok here is the first notice when the back cover is open phone work very smooth not even tiny false tabs, but double tab to wake up not working at all also proximity sensor very slow to respond

 

[Hesham Fouad]

so while the back cover is open the phone working excellent with 0 false tab, but the double tab to wake up the phone become disabled as well option to hover your hand over the screen to see the glance i dont know why ,maybe it need to touch something with the back cover ,any way i closed the phone and problem back again
so i tested the following
soft reset the phone then turn off double tap to wake up the phone and then restart the phone after to make sure it take effect ,restart is important and ,
and of course i turned on all other features like automatic brightness,sun readability,high touch sensitivity to make sure the problem is only related to double tab
till now so far so good, i will test it till 2moro and let you know my final conclusion
If this working I will check later all the wires located in the back cover thank u everyone

 

[seb_r]

As a 1520 owner I follow this thread for a while and wonder why people still digging here about it. A while ago I postes already that at least for me the reason is 100% hardware related. Keep things simple: the operating system, drivers and firmware of the OS is the same for all users. So as some user have this screen issue it only can be hardware related.
Why a restart of the phone or any update of the firmware or OS (and the folling reboot) seems to fix theproblem for a while is simply because on a restart also the hardwardware is reinitialized.
There are three issues that I observed could cause the erratic behavior. The first one is the digitizer itself: I noticed the screen has very variable sensitivity: some areas on the screen already register a tap while the finger is still hovering and not touching the screen. On other areas you almost need to press on the screen. The second source of problemjs can be the size leading to flexing of the board or the display. Connectors could come off partially, components get too close or even make contact. That would also explain also why the screen sensitivity issues only happen after weeks or months of use. And the third and also very likely explanation is EMI (Electromagnetical Interference) - the device's own interference causing problems back to the device itself. This can occur due to improper board layout, component placement and spacing, missing or inadequate shielding. To fix this would requiure a re-design of the PCB, not to mention the testing to find what part or circuit caused it which is even more time-consuming.
Well, no matter what the source of the problems is but either of the above would be very costly to fix as large parts of the phone have to be reworked and replaced. So no wonder Nokia / MS abandon and ignore this topic, even for their flagship device.
Unfortunately I cannot offer you a fix but a good advise: get your phone from a reputable seller as its very likely that you have to deal with them when the problem occurs. Better aim toward a replacement / refund from the seller than any repair efforts from Nokias warranty partner.

 

[l1520orAFK]

For me, the issue is that whilst you're still touching the screen, there's a brief disconnection and followed by a reconnection again. This causes the false tap, there phone think you lifted up your finger and retouched the phone again. What causes this disconnection? It could be the explanations above. I don't have statistics on which settings or combination of settings which lowers the chance of this happening. But it happens nonetheless. Nokia just doesn't have the necessary manufacturing expertise unlike Samsung. Lets hope Microsoft can find better consultants.

 

[sklchan]

so while the back cover is open the phone working excellent with 0 false tab, but the double tab to wake up the phone become disabled as well option to hover your hand over the screen to see the glance i dont know why ,maybe it need to touch something with the back cover ,any way i closed the phone and problem back again
so i tested the following
soft reset the phone then turn off double tap to wake up the phone and then restart the phone after to make sure it take effect ,restart is important and ,
and of course i turned on all other features like automatic brightness,sun readability,high touch sensitivity to make sure the problem is only related to double tab
till now so far so good, i will test it till 2moro and let you know my final conclusion
If this working I will check later all the wires located in the back cover thank u everyone

As you're doing the test willingly, I've a request, please help all of us here to take more/lots of clear and high resolution photos of your opened back cover phone. A few crystal clear photos win thousand words. Snap as detail as possible because there's not much Lumia 1520 internal photos around.

 

[Hesham Fouad]

here is a photo with red mark on spot areas that will be in contact with the back cover ,like i said before no false tap when the back cover is open just a firsm and excellent touch ,also double touch to wake up the phone was not working during the back cover is open
once i close the back cover the false tab back again,
so i left up the grounding contacts as described in service manual (location top red marks on photo) and am testing again

 

[l1520orAFK]

WOW PRAISED. but how to circumvent with back cover in place, I can't walk outside with this phone open LOL

 

[HoosierDaddy]

I want to throw out my experience with the first 1520 I had to see if it provides any more clues.

My 1520.3 didn't have these issues for the first 5 or 6 weeks I owned it. Then I ran a benchmark suite posted in these forums. Immediately after finishing with no intervening handling of the phone, all the symptoms appeared and in the extreme. The phone would alternately ignore touches and imagine touches even when it was just sitting. Soft and hard resets and a reflash with Nokia Recovery tool had no effect. My best guess was that the benchmark overheated some component which then triggered the problems. But who knows.

Fortunately B&H replaced it and the replacement does not have the problem but I don't run benchmarks, just in case.

 

[sklchan]

View attachment 86511
here is a photo with red mark on spot areas that will be in contact with the back cover ,like i said before no false tap when the back cover is open just a firsm and excellent touch ,also double touch to wake up the phone was not working during the back cover is open
once i close the back cover the false tab back again,
so i left up the grounding contacts as described in service manual (location top red marks on photo) and am testing again

Thanks a lot for the photo sharing, I've run across the service manual and match up those mentioned back cover contact point and seem non of it related to screen but ONE at the PCB other side there's a huge ESD Grounding pad that permanent attached to the digitizer/LCD with only 2 tiny protruded metal pin that make contact with the main board shield, could it be these 2 pins failed to properly ground the panel??? as when you've detached the back cover the main board pressure toward this pad might be remove and make contact with the shield but once re-attached the back cover it will be compressed again (which causing misalign and lose contact with the shield)?? I just guessing, as since you've opened your unit you might as well run a check on these 2 tiny pins condition, it maybe your surprise to found it might have broken... observe that possible contact shield having holes within make me wonder the grounding pad metal pins might not properly touching the shield if it goes into the shield holes...

LCD Grounding pad location:


LCD Grounding pad possible contacting point:

 

[Hesham Fouad]

the 5 screws holding motherboard are very very loosen by default this lead to weaker grounding ,just tighten them and you are done, or keep bending the phone

 

[l1520orAFK]

I saw a similar post at Nokia official forum but it got removed due to forum policies. Anyway they also mentioned something like a double tape solution to raise the grounding. I'm pretty sure Nokia is aware of this but idk why they don't try this fix - or at least we don't know if the repair center is reluctant to follow any repair not in the official procedures.

So this problem at least will unlikely appear in future phones.