Develop Bugs

[Q] how does the touch screen work ?

After the sprint service reset my phone and killed my calender, I got an automated message asking if my problem was resolved. Well then I pulled over and brang up the dialing pad on the screen and started trying to press the numbers but as with 90% of the time they do not work. I started licking my fingers and pressing on the display and started *****ing and my 17 year old daughter asks my what I am doing , she than says why don't you calibrate my display. That would be great if there was one! She has. An lg touch and hers has one but mine don't she asks? Now I need to know how to make mine work before I poke my finger through the screen. I can't even hang up the phone 50% of the time. Is there a secret way to use this touch screen or do I just have to use the right finger and licking my fingers to make it work just ain't right.

Capacitive touch screens, do not need to be calibrated, unlike their cheaper cousins, and if you are having accuracy issues you need to either Odin the phone or bring it to Sprint and let them do it.

http://en.wikipedia.org/wiki/Capacitive_sensing

Licking your fingers?!? That's totally unnecessary good sir/ma'am. Capacitive screens work by picking up the electrical charge that we have in our bodies. So when we touch the screen, that charge is sent to the display, the sensor and cpu do their thing and figure out where the screen was pressed. That's why you can't use the screen with gloves on (like winter gloves). Anyway, it just sounds like the phone is acting wacky.
Have you just tried rebooting to see if that fixed it? Or turning the screen on and off a few times? My phone acts weird on the lock screen sometimes and just turning off the screen fixes it.
There are a few threads here that address accelerometer problems but if the screen is just not picking up your touch, you may want to take it to Sprint.

that would be sir and it is just one of many problems my phone has. I reset it ,sprint reset it, I am crossing my fingers I got a dud . I was suckered onto the shorter waiting list and had the phone since launch day and in the beginning it was told to me by radio shack that android 2.2 was shortly comming and was going to fix all these problems I am having. I love the phone when it is working correctly but now I am just tired of the issues and promisses not being fullfilled. I read the article in the posting and it explaines different kinds of capacitive tec, gut wich one does the epic have. my wifes epic is so sensitive that it senses 1/4 inch away at times. mine is a luck of the draw and her phone is not mine so I dont use hers enough to see if its really better. I *****ed to sprint enough ,and it took this long, that they are sending me a new one. I doubt they are sending me a new one and expect they are sending me a refurbished one to test. I want to make sure its not something like my fingers not having enough energy to sense or cosmic rays are making my page back button go wacky by itself at random when texting or browsing.

Lol, if cosmic rays are bombarding your phone, we all have a lot more to worry about than the responsiveness of your phone! Sounds like you may have just gotten a bad phone. I would be pissed if Sprint tried to give me a refurb phone. There's a command somewhere in the scripting history on the phone that will tell you whether the phone is refurb. I don't know how to do that. I bet someone on this site does though. I guess the bottom line though is that the phone just needs to work.
And to your wife's phone, yes, the phone can be extremely sensitive. Sometimes, I swear that I didn't touch the screen but the screen registers a touch just because my finger was really close to the screen.
Finally, you may want to flash your phone. If you are not comfortable using ODIN or adb, get Sprint to do it. And not just a factory reset through the settings menu. I mean resetting the phone through recovery or download mode. Good luck.

[Q] Backlight starting to die?

Don't know if anyone else is experiencing this with their Play but as of a week or two ago the backlight started acting strange. The backlight will randomly stay off when I push the power button with the slider gamepad closed. Only way to make it come on is to pop out the slider. It seems to be random, and if I push on the slider edge slightly with my thumb with the slider closed the backlight randomly flickers, ranging from slight to severe.
The display is still working despite the backlight issues, I can open apps, and use the phone normally but the backlight flickers on and off. Makes it especially hard to use the phone in the dark.
Phone has never been dropped once.
I've replicated this problem with a variety of roms, both custom and stock. It's definitely not app related or even custom kernel related. It happens on a fresh wipe with stock rom with stock kernel. It happens on CM7 with custom kernel.
I'm curious if anybody else is experiencing this. It would tell me if it's just an isolated incident or if others are having this problem.

Sounds like a faulty connection to the backlight to me.

I had the same problem 2 days ago. Then I couldn't get my phone screen on at all!
I sent my phone back to Sony, even thought I bought it second hand. Phoned them up and talked to them. They asked what time of year I bought it so I said around August and then they gave me the address to send it to. Now I'm just waiting to see what happens next.
If your going to send your phone to Sony for repair then make sure you put the fresh firmware back on and un-root your phone as that breaks the warranty (unless they don't know about it)
Hope I helped you. If I did then click the thanks button

Sounds like a faulty ribbon cable to me. (cable that connects the screen to the rest of the phone)
You wouldn't need to drop it for that to go bad, It could just be a case of opening and closing the gamepad or lot.

Yeah good thoughts, most likely the ribbon. That really sucks because I've only had the phone for 7 months, and I've taken excellent care of it. Sounds like a major design oversight.
Mine is probably near complete failure at this point. It's taking a lot more effort to keep the screen on now. Fearing soon it won't work at all.

In hopes that this might help someone else down the line, I was able to fix my problem. Yesterday the screen pretty much quit and I had no choice but to try and solve it myself or buy a new phone.
Using this disassembly video as a visual aid I carefully pulled my phone apart: http://www.youtube.com/watch?v=-3n5ZfkqhzE
You'll need a torx T5 tool to pull out all the screws but they are cheap.
Underneath the phone and jammed into the screen ribbon was a rather thick hair just hanging out. Somehow it buried itself in there. I removed it, unplugged and replugged the screen ribbon and cleaned the dusty inside with a q-tip and reassembled it all together.
It works fine now, so hopefully this helps someone else avoid having to pony up for a new phone. For those under warranty probably best to send back but for those like me with no warranty it's worth the shot.

Touch screen non-responsive in the middle

My Desire Z had a fall, and has developed two problems
1 - The hardware keypad has started to take hard-press and sometimes prints double characters on single press. I think the alignment is out or something... any other guess ?
2 - The touch screen sometimes stops working from an inch up from the bottom and continues to half an inch. Before and after that patch, the touch always works fine . Mostly, the whole touch screen works fine. But when the patch gets non-responsive, I have observed that by turning the screen off and on a couple of times makes it work again. I am not very sure what the problem is. Any clues ?
Thanks

I'm also experiencing a similar issue - for me it's usually an area that corresponds to the top row of the
on-screen keypad (for unlocking) or the top of the area for unlock patterns (portrait orientation).
Mine is a 2 year old DZ w. Cyanogenmod 7.1
No HW key problems & no droppage.
Liberal application of isopropyl alcohol and a microfiber cloth - especially around the edges of the screen
seem to help a little bit but not often enough to be better than random.
Switching the screen off and on occasionally helps but most often I get annoyed and use the HW keys to
unlock.
I have noticed that, after powering on the device, the SIM-lock keypad works just fine but the (different)
screen-unlock keypad fails. This leads me to believe it to be a software issue.
/b

I have had this experience on my G2
No fix for me but his my experience check out the url!
http://forum.xda-developers.com/showthread.php?p=31264095
Sent from my HTC Vision using xda premium

Thread moved to Q & A section.

So i am going for Digitizer replacement will post the result when the phone is back.
And what about the Keypad taking hardpresses ? what can be the issue there ?

so my desire z is in the shop for repairs. lets see what problem is diagnosed.

I have read in another thread in this forum that the hardware keyboard (need to press hard on some buttons) issue can happen when the phone falls.
Apparently, the flat cable that connects the keyboard to the rest of the phone gets loose and causes such trouble.
Since your phone is in for repair, I'm sure this will get sorted when U get it back.

ok so my phone got back from repairs, the guy couldnt fix the touch-screen rather made it worse. Now the touchscreen doesnt work at all. So i cant unlock the phone and cannot test the Keyboard problem. The guy said the touch problem is related to the ribbon cable and not the touchscreen itself.
Note 1: He says he tried replacing the touch panel altogether but it didnt work.
Note 2: I still think the ribbon is fine (call it intuition)
Note 3: I am giving my phone for repairs again, but this time to HTC service center which would probably cost me a lot more than third-party repairs but at least it will get fixed.
I will update when I my phone back from HTC service center.

Could you not unlock the phone by opening the keyboard ?
It does smell to be an issue with flat (ribbon) cable to me as well. As if there was some loose contact before (caused by you dropping it), and after the repair guy took the phone apart, he probably made even bigger mess by ruining the flat cable completely.
From my experience (and I've claimed warranty 3x for the broken digitizer (touch panel)), if it's broken, an area of the screen (or the whole screen) will be permanently dead. It would not come back to life every now and then.
btw, mine always started being unresponsive in the very middle of the screen, a bar of height around 1 cm (somewhat less than 1/2 inch). Each time they replaced the digitizer.
If it;s the flat cable, you shouldn't end up being charged too much - those thingies are very cheap (in China) and the labour will probably be the majority of the price. Fingers crossed.

So I got my phone back again... The HTC repair center was not located in my city so I went to another (better known) repair shop. The guy said, "your phone hasnt been opened at all from the touchscreen side, any *repair guy* who claims he has opened it and tried this and that but couldnt fix is simply lying. This said, he opened up my desire z replaced its Touch Panel and voilah! my desire z is sensing again in 15 mins

What's the status for the keypad and need to press it hard to work ?

nope... I had it cleaned using alcohol / thinner. now it works fine.

So, I updated to CM 7.2 last night but the touchscreen problems are still there.
Updated using CWM and deleted data & cache whilst doing so.
I really hate the prospect of getting a new phone as the current models available
in DK are all without physical keyboards

[Q] Weird touchscreen behaviour (only works when keyboard is flipped out?)

Hi everyone,
I've had my Desire Z for little over 2 years now and two months ago (was running CM7.2 at the time) I started getting a weird issue where my touchscreen would only be responsive when the keyboard was slid out (so the opposite problem of what quite a few other people have reported where the touchscreen becomes unresponsive when the keyboard is out). The status LED would also stay off whenever the keyboard was closed, and the keyboard backlight didn't come on anymore at all. Also, I had to make sure that the keyboard was slid out during boot, if the phone booted without the keyboard out the screen would not become responsive at all until after another reboot. My earpiece speaker stopped working around the same time so I was wondering whether it was just an issue with the flex cable becoming a bit loose, but the touchscreen would consistently start working again when I flipped the keyboard out, and also the physical scroll button on the top bit would always work, so I was still hoping it would be some weird software issue.
I then upgraded to Flinny's (amazing) Andromadus ROM (build 22, complete data+dalvik wipe) after which the keyboard backlight started working again, but the rest remained pretty much the same. Since then the touchscreen issues have been getting worse, so that I sometimes have to flip the keyboard in and out again a few times, or turn the screen on or off with the power button several times before it becomes responsive again, but then it tends to work fine until I lock the screen again, with no noticeable dead spots anywhere on the screen. I've had days where it worked all day without problems (except having to flip out the keyboard, that's been a constant for the past two months), and then today I haven't been able to get the screen to do anything at all even after dozens of reboots.
I've already bought a new digitizer and am all ready to put it in (I'll have to replace the broken earpiece anyway), but was wondering whether anyone has any thoughts on whether it could still be a software issue after all, or if anyone has experienced anything similar? The thing with having to flip the keyboard out to get not only the touchscreen but also the status LED to work is just so weird and makes me doubt that it's a pure broken digitizer or lose flex cable issue, so I'm wondering whether it would be better to first try reverting to a stock ROM before taking on the messy sticky glue stuff (I should be fine but still, never done it before)?
Many thanks!

From what you describe my best guess would be the main flex cable is what needs to be replaced. Flash a touch based recovery and see if you have the issue there as well, if so its very unlikely that its anything but a hardware fault
Sent from my Nexus 4 using Tapatalk 2

Thanks for the heads-up, I've been playing around a bit more with software and I do manage to get the screen working again occasionally, typically after the second boot into a newly flashed ROM or restoring a backup, and only until one or two reboots later when it becomes completely unresponsive again. I've tried CM 7.2.0 as well as Flinny's Andromadus 10, and it is only complete flashing that does the trick, cache wipe or factory reset alone does nothing. The two occasions where the touchscreen worked were still limited to when the keyboard was flipped out, and it also had to be flipped out during boot, otherwise nothing would work. I've learned to navigate my way around the phone by just using the hardware navigation button, but I'll have a close look at the flex cable when I take it apart to replace the earpiece speaker tonight...

Hello,
so I took my dear phone apart yesterday to replace the broken earpiece - everything went fine but after reassembly the replacement earpiece isn't working either, which leads me to think that all those little broken bits might actually be related to some contacts being a bit lose, all in the same region. Should've thought about that earlier really since the earpiece and the LED (only works when keyboard flipped out) are both in that top region that the digitiser data presumable also has to run through before passing through the flex cable.
In any case, I also took a picture of the flex cable which is slightly bent but doesn't seem straightforwardly damaged (see attachment, that thing on the right is *not* a rip). Think it's worth trying to replace it anyway?
What was truly bizarre is that after the first boot following reassembly the touchscreen worked quite consistently for the entire evening - I thought I might've fixed a lose contact by un- and replugging the digitiser cable, but then the screen went nonreactive again at some point. I wonder if the working screen was again actually related to some software reset caused by the battery being taken out for so long? In the meantime the actual screen and trackball are still working away perfectly. Bizarre.

Just to let people know the solution to the mystery: the increasingly odd behaviour was actually caused by an initially small rip in the flex ribbon cable that got bigger and bigger - it's actually half-visible in the picture I uploaded above, only that the rip is where the cable comes out from underneath the case, and not where it's wrinkled!
Just in case it could be useful for anyone, here's the (top half of phone) components in the order in which they failed on me, which I guess corresponds to the order of the respective data lines in the ribbon cable (from the top of the phone towards the center):
environment brightness sensor (I thought that the sensor had been broken for almost a year, but as soon as I rebooted with the new flex cable I noticed how my phone stopped shining into my face at full brightness - if your brightness sensor gets stuck reporting the same (low) value this means your flex cable is on its way out!)
earpiece speaker
status led
touchscreen
screen (non-alignment with edge of screen, visual artefacts)
screen (fade to black/power interrupt)

obstacle3 said:
Just to let people know the solution to the mystery: the increasingly odd behaviour was actually caused by an initially small rip in the flex ribbon cable that got bigger and bigger - it's actually half-visible in the picture I uploaded above, only that the rip is where the cable comes out from underneath the case, and not where it's wrinkled!
Just in case it could be useful for anyone, here's the (top half of phone) components in the order in which they failed on me, which I guess corresponds to the order of the respective data lines in the ribbon cable (from the top of the phone towards the center):
environment brightness sensor (I thought that the sensor had been broken for almost a year, but as soon as I rebooted with the new flex cable I noticed how my phone stopped shining into my face at full brightness - if your brightness sensor gets stuck reporting the same (low) value this means your flex cable is on its way out!)
earpiece speaker
status led
touchscreen
screen (non-alignment with edge of screen, visual artefacts)
screen (fade to black/power interrupt)
Click to expand...
Click to collapse
I'll for sure keep that in mind. Mine is still going strong for the time being, but it's good to know some warning signs if I need to replace parts or if it's time to get a new phone

fireball0093 said:
I'll for sure keep that in mind. Mine is still going strong for the time being, but it's good to know some warning signs if I need to replace parts or if it's time to get a new phone
Click to expand...
Click to collapse
Replacement parts all the way, the repair was 15$ and it feels as good as new! Well, it could do with a new battery but that's just another 5..
Just realised that the proximity sensor should actually be added to the very top of the list - just noticed that faint red light when taking a phone call, don't remember seeing that in almost a year :]

obstacle3 said:
Replacement parts all the way, the repair was 15$ and it feels as good as new! Well, it could do with a new battery but that's just another 5..
Just realised that the proximity sensor should actually be added to the very top of the list - just noticed that faint red light when taking a phone call, don't remember seeing that in almost a year :]
Click to expand...
Click to collapse
That's not a bad cost at all. I know I'm going to have to replace my keyboard in probably 2 months or so (maybe sooner) because some buttons are starting to not work. Other than that fact my phone is currently still going strong for being going on a 3 and a half year old phone

Weird touch screen.

Its been some days, I'm experiencing this weird touch screen problem.
My DZ touch screen doesn't respond properly.
For example:
If i see an image and slide just one finger up and down then it would zoom in and out. And then the whole screen becomes unresponsive.
It seems as if, its touched by itself. Even the softkeys would go numb. Only the haptic feedback of my search button works at that moment.
But the trackpad works perfectly.
But, If i lock and unlock the screen using power buttons, it would work properly for some few moment and then again the problem repeats.
At present I'm repeating this process of locking and unlocking screen to use my phone.
One even worst weird thing is that, if the device is connected to a charger and kept on the table or floor. This problem doesn't occur.
I have done system format, restored my nandroids and even changed Roms. The problem still exists.
Please note, i don't use any Casing or covers that would press the device hard for malfunctioning of screen. I have even removed and replaced my screen guard.
I'm sure, its not a software issue.
And even i dont think its a strip issue, because i dont use my physical keyboard always.
Can anyone say what hardware issue it might be..?
Or what i need to do? I'm really out of options.
Do i have to replace my whole screen or the digitizer..?
Thanks...

Thats no fun,
As you stated it's more than likely a hardware fault, the two most likely culprits would be the digitizer or the main flex cable
Which would be this and this
both relatively easy to replace depending on your experience
in 4.x and up ROMs check the developers setting to show touch or use apps like
z device test
or
yet another multitouch test
these wont help you fix the issue but may show you where the bad points are on the screen
best of luck

I know the problematic spot. Its near Search softkey. Even Yet another multi-touch test would stuck at that spot....
As you can see in the image, that i'm not holding anywhere, still it shows that somewhere around Search softkey its touched by itself.
In second image, If i move my fingers around, it would show the other touch responds, but if i slide near search, it would go and stuck there itself.
So, i guess i would first go with the flex cable.

In actuality I'm leaning toward the digitizer in your case, but its possible to be either.
And if you have a spare phone it may be worth disassembling even without buying anything. On a G1 I once fixed a similar issue just taking out the digitizer and cleaning the contacts on the ribbon and the edges of it as well, when I put it back it worked like new. I think some dust may have gotten into the edges but it may be worth a shot before buying anything... But could make matters worse so if you don't have a spare, buy parts first
Best of luck
Sent from my Nexus 7 using XDA Premium 4 mobile app

I guess i should try disassembling and clean it first. If it still persists then i would go for digitizer.
And thanks for giving a hope.
Thanks...