Database Users

Touch screen broke

Hi! I Love ( D ) my TD2... to bad my touch screen broke already (2 months after purchase) without dropping it or whatever.. Screen and phone works normal.
Im just curious if there are other people having this problem jet?
Do you guys think im f*ck'd? or does htc replace touchscreens within warranty?
if not; Does anybody know what the costs may be for replacing a touchscreen? And is it possible to replace only the touchscreen or must the whole screen be replaced?
A lot of questions , i know.. hope someone can give me answers.
Thank you!

new screen
see here, a similar discussion: http://forum.xda-developers.com/showthread.php?t=537654
if the screen broke and it was not your fault, warranty should cover that ... it seems that buying a new screen and putting it is easy ...

thnx for reply georgeono! guess i'll try warranty first.

same here...touch screen cannot sense any form of touch

Hm.. to bad man. when i put my phone under a bright lamp or in the sun i can see some kind of liquid under the screen(so i know its definitely broke..), same at yours? did you contact warranty jet?
i guess the screen is just not that strong, cause i have treated this phone much much better then my old htc touch and that touchscreen is still working..

my batt went flat...
I go home and charge it..
before full charge, I sms and it is not working anymore..
Soft reset or hard reset no use..
Next day, I see the "liquid" screen under sunlight...
I also take care of it well as this is my first pda and most expensive hp i ever bought...
Going to sent in on this coming thursday...
How about ur warranty, void or consider under warranty??

havent found time jet to send it in but i'll send it tomorrow so i'll let you know. .

I have had the same problem. I sent it back last Friday and have had notification on Monday that it arrived at HTC, but the tracking details they gave me don't seem to do anything. They say it'll be 5 to 10 working days before I get it back.
The engineer on the phone pretty much straight away described the problem as 'LCD Leak' and that was also stated on the postage label they sent through to me.
I found a short term fix for the problem before i sent it off: When you see the touch screen has the patch of liquid inside, use a piece of sellotape or other sticky tape and gently pull the touchscreen outwards away from the phone and it becomes usable again as long as no fluid is touching the screen any longer.
Hope this makes sense.
edit: I got my phone back and the same problem was still occurring - it looked like they had simply take taken the screen off and put it back on again. It has gone back again, but hopefully this time they will actually look at it.

hm i tried your fix but it didnt work for me ..thnx for the tip anyway!

Same like here I think:
http://forum.xda-developers.com/showthread.php?t=522813
I had to sent it back for a repair. Right now my repaired phone starts to get the problem again

kaas11 said:
Hm.. to bad man. when i put my phone under a bright lamp or in the sun i can see some kind of liquid under the screen(so i know its definitely broke..), same at yours? did you contact warranty jet?
i guess the screen is just not that strong, cause i have treated this phone much much better then my old htc touch and that touchscreen is still working..
Click to expand...
Click to collapse
i had the same problem and i can tell you this is caused by too much pressure on the screen. it seems the screen does fall into the phonecase and therefore free itself from the glass. take care with that phone in the pocket!! also the manual says, take out the phone of the pocket when you sit down!! i was shocked when i read that... i mean.. wtf.. what is the idea of a mobile phone which you cant have in your pocket???

haha , and they used to call it a pocket pc! too bad i havent read the manual BEFORE i bought this fragile peace of sh..

kaas11 said:
haha , and they used to call it a pocket pc! too bad i havent read the manual BEFORE i bought this fragile peace of sh..
Click to expand...
Click to collapse
Your just a very unlucky man...
I really love my TD2 and it's working as it should be.
I do not use a case and have it just "naked" in my pocket (without keys and other stuff in my pocket) and its no problem, no scratch...
And i don't call it fragile, ok... it can break easier than a rock in your pockey but still..... I don't know how your TD2 is but mine cant bend a 1/2 mm, it's pretty though.

Phone fixed.... For now
I have received my phone back after a second trip back to HTC and it appears that they have replaced the whole frontage of the phone as a tiny scuff on the metal bit and a miniscule scratch on the screen have gone. The internals of the phone are the same as it has the same serial number and IMEI number.
Its all working so far, I've had no evidence of the fluid in the screen as yet and hope not to again!
Send it back and it will be mended eventually!

Had a similar problem, after 20 days the display broke (not on the surface but under it) because of...who knows, maybe direct sunlight since it was on the seat of my car.
Now, after reading the post, I see it's not a singular problem but also other lucky customers are dealing with it.
The real problem is HTC service. I contacted HTC Italy and they told me to take the PDA to a collection point along with a letter describing what happened since I asked for the warranty cover. After 20 days they told me I have to pay 126€ to repair my D2 because the service decided that it was due to my manomission (aka : you have lied to us). After some enraged mails I sent to them, they replied me I should contact HTC in UK to have the warranty. I decided to pay to have my phone back quickly but until yesterday no answer.
Today I sent another email and HTC replied telling me that the service center is closed for holidays until 24th...
I let you imagine how disappointed I am with HTC and they call it HTC Service Excellence.
Ok, it was my fault...I knew I had to buy the spare part on my own and change the LCD but I trusted the HTC name...big big big mistake!
Just consider those experiences in case you think to send your phone back to HTC service...I will never do this again!
Thank you guys, now I know for sure it was not my fault.

I have my TD2 now 3 month and I recognize the problem others mention. Although this problem is a fault, the system is not broken.
When the phone blocks, look for the "liquid" below the screen. It can be very small to fingertip size. The screen is not broken but the touch screen sticks to the display screen. It occurs by applying some force while using the touch screen. Of course this should not happen but it locks the phone or results in unpredictable touch inputs. IT IS NOT BROKEN.
It can be easily solved. Just wipe, with some pressure, with your thumb over the touch screen starting from well below till above the affected area. The touch screen detaches from the display screen and everything works again.
The solution would be a mod by HTC to prevent the two screen from sticking together.
I hope this helps by preventing people to send their phone back and foreward unnescessary.

Just send in my TD2 today for the same reason. Hope they wont simply "lift the surface up" and send it back to me.

repaired!
i had to wait a long time, but i got a message today that the phone is repaired within the warranty by an external repair service. Hopefully the problem is solved now, but im very glad to hear its not gonna cost me 200 euro's or so!
for the dutch : ondanks alle slechte verhalen over dynafix (volgens mij de gebruikelijke repair service voor een htc telefoon in nederland) is het toestel gewoon gerepareerd zonder onzin over drukschade etc. !

update
got my phone back yesterday , in fact they replaced my old phone with a brand new one! Totally free of costs. So i'm a total htc fan again!

kaas11 said:
got my phone back yesterday , in fact they replaced my old phone with a brand new one! Totally free of costs. So i'm a total htc fan again!
Click to expand...
Click to collapse
Are you sure it's new? I thought they replaced mine as well (after a LOT of phone calls and hassle), but the serial number is still the same.
The counters had been reset, so at first I thought it was a brand new one...

Digitizer Non Responsive

Hey guys.
Owned the phone for a few months now and have started to notice a really odd problem. For a while the screen was being fairly unresponsive to touches and I couldn't figure out why. Taking the screen protector off fixed it temporarily but now the issue is back.
I finally realised that the issue was a black smudge that would appear whenever I pushed too hard on the screen. I'm assuming this registers as a touch on the screen and prevents it from working. Rubbing the stylus over the area usually makes it dissipate and the screen becomes responsive again, but it would come back not long later after general use.
Also there's some fairly odd rainbowing underneath the digitizer that moves around when you press on the screen. It circles around the smudges when they appear.
I know that all sounds fairly vague, but any help on the issue would be great. Is a new digitizer in order or could it be fixed by just dissassembling it? I've tried using a suction cap to make the problem go away, the rainbowing disappears but slowly comes back again. Also I haven't dropped the phone, left it near anything etc, besides the digitizer problem the phone works fine.
Thanks in advance!
(On a side note, I bought the phone off eBay and had to use a serial number locater to determine the region of the phone. Found out it was destined for India when I'm in Australia. Fairly odd, but what are the warranty implications? Is it still covered?)

Same problem here!
I've sent it to HTC for repair, since my Diamond2 has 1 year warranty and I only bought it in May/09. HTC said that screen issues are excluded of the warranty and that I have to pay about €70 for the screen repair, because, they say, the problem is due to misuse - wich I don't think is true.

Daisjun said:
Hey guys.
Owned the phone for a few months now and have started to notice a really odd problem. For a while the screen was being fairly unresponsive to touches and I couldn't figure out why. Taking the screen protector off fixed it temporarily but now the issue is back.
I finally realised that the issue was a black smudge that would appear whenever I pushed too hard on the screen. I'm assuming this registers as a touch on the screen and prevents it from working. Rubbing the stylus over the area usually makes it dissipate and the screen becomes responsive again, but it would come back not long later after general use.
Also there's some fairly odd rainbowing underneath the digitizer that moves around when you press on the screen. It circles around the smudges when they appear.
I know that all sounds fairly vague, but any help on the issue would be great. Is a new digitizer in order or could it be fixed by just dissassembling it? I've tried using a suction cap to make the problem go away, the rainbowing disappears but slowly comes back again. Also I haven't dropped the phone, left it near anything etc, besides the digitizer problem the phone works fine.
Thanks in advance!
(On a side note, I bought the phone off eBay and had to use a serial number locater to determine the region of the phone. Found out it was destined for India when I'm in Australia. Fairly odd, but what are the warranty implications? Is it still covered?)
Click to expand...
Click to collapse
You have collapsed your layers between lcd and digitizer.
Some folks here use duct tape to repeatedly pull the layers apart and it fixes their issue for a while.

Thought it'd be something along those lines. I'll give the duct tape trick a try, can you point me to some other threads? I tried searching but was probably using the wrong terms.
Also vasco that's complete bollocks. I've kept my phone in its case the whole time I've had it, never put any pressure on it or had it in a rough environment. I'd throw a few customer complaints their way, especially if other people have had the same issue. Nice to know I'm not alone at least.

Daisjun said:
Thought it'd be something along those lines. I'll give the duct tape trick a try, can you point me to some other threads? I tried searching but was probably using the wrong terms.
Also vasco that's complete bollocks. I've kept my phone in its case the whole time I've had it, never put any pressure on it or had it in a rough environment. I'd throw a few customer complaints their way, especially if other people have had the same issue. Nice to know I'm not alone at least.
Click to expand...
Click to collapse
search for "newton rings"

Daisjun said:
Thought it'd be something along those lines. I'll give the duct tape trick a try, can you point me to some other threads? I tried searching but was probably using the wrong terms.
Also vasco that's complete bollocks. I've kept my phone in its case the whole time I've had it, never put any pressure on it or had it in a rough environment. I'd throw a few customer complaints their way, especially if other people have had the same issue. Nice to know I'm not alone at least.
Click to expand...
Click to collapse
The issue is being discussed here:
http://forum.xda-developers...522813
I've already filed a complaint to the comm's regulation office. I'me presently waiting for their response.

had the same issue.. I just replaced the digitizer, it's a bit tricky but certainly possible.. yours is not that old so it should be repaired under warranty if you can have that done (have no clue about your situation there..)
digitizers are cheap on ebay
disassembly:
http://www.pdacenter.ru/razborka/htc-touch-diamond2/

Daisjun said:
Thought it'd be something along those lines. I'll give the duct tape trick a try, can you point me to some other threads? I tried searching but was probably using the wrong terms.
Also vasco that's complete bollocks. I've kept my phone in its case the whole time I've had it, never put any pressure on it or had it in a rough environment. I'd throw a few customer complaints their way, especially if other people have had the same issue. Nice to know I'm not alone at least.
Click to expand...
Click to collapse
Here is my thread about this.
I am in the same boat as you - phone was destined for somewhere in Asia, and I am in Australia. I contacted HTC, and they also told me that the problem could be caused by misuse, even though I KNOW it wasn't, as my phone is always in it's case unless being used, never dropped etc. It sucks, but I think I will just replace the digitizer myself.

CDMA Hero Bugs and Manufacturer Defects

I'm starting this thread as a central database for CDMA Hero owners to share defects and bugs in Hardware and Software.
My apologies if this has been addressed else-where.
Found with my Girlfriend's and my "with Google" Heros that we both have a noticeable amount of dust under the screen (glass). I thought this was addressed with rev. 2 of the phone?
Anyone one else with the same issue?

paint on case is VERY easy to chip...

I agree the finish seems a little delicate. I've been using a cheap hard plastic case since I got mine in dec. Helps alot with wear and tear, and isn't too bulky or hard to get out of my pocket.

i agree with the paint issue.
my end button is totally red not silver and red

I had a dust issue with my first (unbranded).
The first thing I did with my replacement (with google) hero was to apply an invisible shield to it. I have not noticed any dust under the screen whatsoever.
Also, although it isn't exactly pretty, I found while applying the invisible shield that it did not cover the gap between screen and button pad. As a quick fix to this I cut a thin piece of invisible shield material that was left over and applied it over the crack/screen protector/button pad protector. Just for some extra protection.
For shocks, I have the phone in the HTC silicone case. My phone has taken a number of falls/skids across the ground and stuff and this combo has protected it completely.
Edit:
Almost forgot, my original also seemed to develop a wear mark on the metal button pad finish. It was as if a part of the layer had rubbed off and tarnished in a circular pattern.

about the dust under the screen...
i contacted htc about before. the person who i emailed replied to me saying that htc has a permanent fix for the problem, so you can send it in and they'll replace/clean the screen and apply some fix to it. catch is, you have to pay for S&H and you'll go without a phone for a bit

justinisyoung said:
about the dust under the screen...
i contacted htc about before. the person who i emailed replied to me saying that htc has a permanent fix for the problem, so you can send it in and they'll replace/clean the screen and apply some fix to it. catch is, you have to pay for S&H and you'll go without a phone for a bit
Click to expand...
Click to collapse
I have a ridiculous amount of dust in the lower left hand corner of my screen... so much so that part of the screen isn't visible anymore. Do you think Sprint would just let me exchange it for a new one? Or would I still have to go through HTC?

mrinehart93 said:
I have a ridiculous amount of dust in the lower left hand corner of my screen... so much so that part of the screen isn't visible anymore. Do you think Sprint would just let me exchange it for a new one? Or would I still have to go through HTC?
Click to expand...
Click to collapse
well i e-mailed htc about this twice. the first time they said that if the dust got bad enough, i could send it to HTC and they'd repair it. they also said this:
I understand how frustrating it can be for dust to collect under the screen of your device. We have recently learned that Sprint has a process in place to resolve this issue. Please contact Sprint for the location of your nearest Sprint Service and Repair facility. They are equipped to clean your device, and in doing so will be able to keep the issue from recurring in the future. I apologize for any inconvenience you may have experienced.
Click to expand...
Click to collapse
which pretty much means that the sprint store should be able to repair it for free.

justinisyoung said:
well i e-mailed htc about this twice. the first time they said that if the dust got bad enough, i could send it to HTC and they'd repair it. they also said this:
which pretty much means that the sprint store should be able to repair it for free.
Click to expand...
Click to collapse
That's great to hear! Nice to know it's not like my Mogul was. They just kept giving me broken phones until I bought my hero....

I had heard about the dust problem before, and was glad that I didn't have that problem yet... After reading this thread, I decided to look again.... Now I do have dust in the bottom right
It seems to me that the problem is dust entering between the keypad and the screen, and then getting up underneath of the digitizer which doesn't seem to be against the LCD, which is strange, I think. Most handhelds I've taken apart have the digitizer glued around the edges directly to the LCD. Thank god that HTC and Sprint are actually addressing this problem. If someone does know how and where this seal is applied, I'd love to know. I might be taking mine back before too long, and I always would like to know what they're going to do beforehand.

beyondinferno said:
That's great to hear! Nice to know it's not like my Mogul was. They just kept giving me broken phones until I bought my hero....
Click to expand...
Click to collapse
OMG i loved the mogul till I realized the CPU was slow the whole thing was slow and in my 2 years i went through 8 of them. That was the best money ever spent on TEP
Seriously you guys should have no problem exchanging that phone in warranty without TEP IF you take it to the shop and they cant resolve your dust issue they will ship you a remanufactured phone.

justinisyoung said:
well i e-mailed htc about this twice. the first time they said that if the dust got bad enough, i could send it to HTC and they'd repair it. they also said this:
which pretty much means that the sprint store should be able to repair it for free.
Click to expand...
Click to collapse
This is 100% inaccurate. I'm a Sprint tech and there is no process in place for repairing Hero's with dust in the screen. Sure I can take your phone apart and blow the dust out, but it will come back.

clamknuckle said:
This is 100% inaccurate. I'm a Sprint tech and there is no process in place for repairing Hero's with dust in the screen. Sure I can take your phone apart and blow the dust out, but it will come back.
Click to expand...
Click to collapse
ffffffffffffuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuu-------------
So is HTC actually 'fixing' the problem?

brian2220 said:
i agree with the paint issue.
my end button is totally red not silver and red
Click to expand...
Click to collapse
Same here. Otherwise no issues.

The stock roms sucks.
But seriously, same as everyone else
-Dust under screen
-Button paint chipping off

At least it isn't near as bad as the Touch Pro. My buddy and I both had one; he still has his... His volume buttons literally fell off, and all of the chrome stripping is held on with scotch tape. The sliding screen has a slight swivel to it. And, thanks to Microsoft, all of his texts are from 1016.
Actually, I'm considering taking my Hero apart and trying to figure out a fix on my own. I think I'll wait just a little longer... just to make sure nothing fails and I can't take it back. Or, is there anywhere I can buy those black stickers for the screw-heads?

I'm surprised none of you guys have seen this yet.
http://androidforums.com/sprint-htc-hero/22036-sprint-htc-hero-disassembly-diy.html

chococrazy said:
I'm surprised none of you guys have seen this yet.
http://androidforums.com/sprint-htc-hero/22036-sprint-htc-hero-disassembly-diy.html
Click to expand...
Click to collapse
OMG they murdered a Heroc!!!

thematrixkid17 said:
At least it isn't near as bad as the Touch Pro. My buddy and I both had one; he still has his... His volume buttons literally fell off, and all of the chrome stripping is held on with scotch tape. The sliding screen has a slight swivel to it. And, thanks to Microsoft, all of his texts are from 1016.
Click to expand...
Click to collapse
Interesting, I loved my Touch Pro, the only flaking or issues with the aesthetics I had were from where it met pavement once...there's also a .cab file your friend can download that will fix the date issue...I'd post a link but I'm not sure of XDA's linking policies to other sites, just google ".cab fix for touch pro sms date," it's one of the first results.
As far as bugs and manufacturer defects with my Hero go, I've had the phone for a little over a month now and haven't anything to report...it does lag a little at times but I've yet to find a rooting process that works for my Hero for whatever reason, it's the newest version with the "with Google" branding. The "one touch root" or whatever it was titled from unlockr didn't work, nor did the one I found on android forums.
I didn't get stuck in a bootloader or anything for either process, it's simply that neither one had any affect; I did follow both process to a "T." I'll get around to trying the tutorial I found on here (XDA) one day when I have time, although I must say, I kind of prefer the hacks and tricks of WinMo at this point.

Aridon said:
Same here. Otherwise no issues.
Click to expand...
Click to collapse
same, i just removed the foil completely. just have a red button now.

[Q] Broken screen.. what to do?

Hi all,
this morning I left my tablet at home and when I come back found it with broken glass (I think tmy little brother dropped it, but he doesn't confess)..
Sometimes touch works, more often not.
However.. What can I do? I read that some lcd are not glued properly, and it could be my case, because on the left it's a bit lifted on the center.
In your experience, is there hope that it can be repaired for free?
And if not, where can I find replacement (I only found this: http://www.powerbookmedic.com/Google-Nexus-7-LCD-and-Digitizer-Assembly-p-22606.html , but it isn't available)?
Thank you!
sooooo sad! :/
Pictures of damage: http://imgur.com/a/E7Rkf

diaSalvatore said:
Hi all,
this morning I left my tablet at home and when I come back found it with broken glass (I think tmy little brother dropped it, but he doesn't confess)..
Sometimes touch works, more often not.
However.. What can I do? I read that some lcd are not glued properly, and it could be my case, because on the left it's a bit lifted on the center.
In your experience, is there hope that it can be repaired for free?
And if not, where can I find replacement (I only found this: http://www.powerbookmedic.com/Google-Nexus-7-LCD-and-Digitizer-Assembly-p-22606.html , but it isn't available)?
Thank you!
sooooo sad! :/
Pictures of damage: http://imgur.com/a/E7Rkf
Click to expand...
Click to collapse
At this moment you have Two Options..
1. Sell it on Ebay for Parts you probably get about 50 to 100 at most.
2. Pack it up and store it away in a closet and forget about it. Until the Screens are being sold as parts.
the reason for both options is due to Asus not selling the LCD/Glass at the moment as a Part.
they are still manufacturing the Nexus 7 and soon will be making the Nexus 7 with 3g capability.
so there biggest priority at the moment is to keep making them.
you can send it in for repair with Asus but it will cost you about $160.00 just to get it repaired.
not to mention how much it going to cost you to ship it to them.

is the device frame cracked or damaged broken is the back scuffed or cracked .. Does it look like its been dropped. IS THE Crack on the left side. CAN You post pictures. Answer the above and give some pics and more info..
i know you do not really know for sure .one more question was it moved can you tell for sure rather someone was using it or not ?
If you really feel it cracked laying where you left it . Without anyone touching it . CALL GOOGLE PLAY.. But please do not be dishonest . There is a issue with the screen lift cracking and becoming unresponsive . as well as backlight flashing issues..
Looking forword to seeing pics and more info

[Q] touch issues

I have a NST with glowlight and i have touch issues quite often... when using the keyboard when i touch backspace it touches "h".. when i touch space .. it touches b ... does anyone have these screen issues? it's like phantom touches.. i takes me 5mins to type something

This is a known issue. I just received mine in the mail and it had issues. I found you can clean it and it may help. But for me, since it is brand new, I just had them ship out a new one. If you are not under warranty, I actually just did a factory restore and it stemmed to have helped a bit.

lekofraggle said:
This is a known issue. I just received mine in the mail and it had issues. I found you can clean it and it may help. But for me, since it is brand new, I just had them ship out a new one. If you are not under warranty, I actually just did a factory restore and it stemmed to have helped a bit.
Click to expand...
Click to collapse
ok thx. It's brand new for me also... not even 1 month... do i need to ship back my nook to get a replacement? i bought from ebay... i need to contact who to report the issue? I read when they give u a replacement, they you a refurbished one?
edit: hmmm so this issue is faulty hardware? or it's just cleaniness? and it will happen sooner or later on any nook? will a cover help?

yeahman45 said:
ok thx. It's brand new for me also... not even 1 month... do i need to ship back my nook to get a replacement? i bought from ebay... i need to contact who to report the issue? I read when they give u a replacement, they you a refurbished one?
edit: hmmm so this issue is faulty hardware? or it's just cleaniness? and it will happen sooner or later on any nook? will a cover help?
Click to expand...
Click to collapse
Nook touch screens use infra-red sensors/emitters located around the edges of the screen. If the transparent plastic sandwiched between the screen and the bezel gets dusty, it can cause problems.

cowbutt said:
Nook touch screens use infra-red sensors/emitters located around the edges of the screen. If the transparent plastic sandwiched between the screen and the bezel gets dusty, it can cause problems.
Click to expand...
Click to collapse
so it's not really a hardware fault but it's because of dirt?? any cover case that can protect against such scenarios? how do i clean it?

I think there are two scenarios (perhaps more). Faulty hardware in which the infra red sensors do not function correctly or dirt/ dust impeding their ability to function. One always hopes for the latter.
The reset I did only helped for about an hour.
First try to clean it.
Since you got it off eBay, start by contacting the seller. Ask the person if it is still under warranty.
Then, contact 1800thebook to get a replacement. If it is not under warranty, I am not sure what your options are. EBay and electronics is always a gamble. Sorry.
~Leko
Go forth and work toward your salvation with diligence.

ok thx,... i have tried cleaning it up but it helps for a few seconds but then it gets freaky at times.. it's a pain to type! do you guys ever take notes with it??? it's impossible...
i don't think it's a hardware issue since the first 2 weeks it works with no problems... i was keeping it in the box while not in use... since i started not keeping it in its box.. i am getting these touch issues... so seems related to dust...
will i need to send back my nook to get a replacement... sounds pretty annoying to do so.. shipping is damn expensive
sidenote: looking at the edge of the nook, i see shiny particles... is this normal or is this dust?

i can't even type my wifi password anymore... every button i touch also "ghost" touch the corresponding middle button.. e.g. when i press d, i get dg ... how do i clean that damn thing? where do i need to clean exactly?? i am cleaning the edge.. does not seem to work.. sometimes it seems ok, then 2 secs later it gets messed up again

Cleaning the screen is a different reason to normal screens. Normally you just want the greasy finger prints off etc. However thats for a resistive or capacitve based touchscreen. NST/NSTG touchscreen works on an infrared array running along the edges ABOVE the screen rather than a stuck on touchscreen so as not to affect the contrast in sunlight.
This means a piece of particulate matter on the screen will affect the touch sensor.
If its confused sometimes it won't work at all! The worst environment to ever take your NST is to a sandy beach, really don't do it.
Personally I use a air duster (compressed air can) to get those pesky bits out of the edges.
When not using NST keep face down to keep out bits of crap or keep in a case..