[Q] u20GT touchscreen mistery - Hardware Hacking General

Hi, sorry if this is a wrong place to post.
Due to some problems with the power socket on my Cube U20 GT tablet, I had to dissemble it. Removed the back cover, soldered the socket in 1 one point ( which was loose) and then simply put the cover back.
The socket was exposed so no screws, cables, adhesive tapes were harmed in making of this operation.Not even touched.
Yet when reassembling , the touchscreen goes nuts after a few seconds ( ghost typing, the screen randomly activates itself and pushes icons)
Back cover removed again,everything is ok. Cover back in its place, the invisible spirits are browsing my Settings and check what HO games I play lately again.
Its obvious that when the case is closed, *something* is pushed or moved and that makes the screen go crazy , but what ?
Like I said before, everything is firmly fixed with their tapes, screws, etc
I`m decently savvy with computers, but with tablets i`m a noob.
Any idea what I should look for ?

Related

My weird Herald experience...

<warning>may be a long post</warning>
Ok, some history first...
I bought my Herald 1 year ago, and after 3 months of proud ownership i dropped it into the toilet. (was just changing to my swimsuit in case you are wondering)...
After that underwater experience, the only kink was that the End button stopped functioning.
Fast forward to the present day. After opening my phone with the help of the service manual i found out that the fault was with the flex cable (the cable that has the keypad buttons, and connects the screen to the phone board)
So i hopped on Ebay and ordered a new cable, along with a new housing as my old one was full of dents, and had the parts delivered today.
I opened my happy ol' Herald, removed the screen protector (this is an important bit, just stay with me) and changed the cable and housing, hoping to transform it to almost-new condition.
After doing the transplant, and hoping that everything went fine, i closed everything and booted the phone up.
The End key functionality was restored, but the Touch Screen STOPPED WORKING!!!. It was registering some very strange positions and as i lifted the pen the cursor was yanking to the right, so i tried the first obvious thing of Align Screen. Since that wasn't registering ANY positions, i reopened the phone, reseated all the cables and still nothing was happening.....
I was at the brim of despair, after 5 hours of screwing, testing, unscrewing etc... and was leaving work... and just as i was packing everything up i picked up the old dirty and worn Screen Protector and tacked it on the screen (and since it was on my office the whole time it got very very dirty).
And lo and behold, everything worked with the screen protector on!!!
So this is the story....
Now, i have a couple of questions:
1) Anyone has a logical explanation about this??
2) I'm afraid to remove the screen protector in case i lose the touch screen again, so now i have a brand-new looking phone with a screen that looks like it was run over. What do you think will happen if i remove it?? (maybe open a poll on this)
3) I also yanked the keyboard (after discovering that its held with Glue on the casing). Now i have it tucked in place but it's not glued. Anyone now what glue is safe to use to make it stick in place ??

Disassembly of Legend (advises & some help required)

Hi there,
I broke my touch screen and tried to replace it by myself.
To make a long story short, I failed miserably (I broke the screen under).
However, I learned a few things I didn't met in the forum.
A- Disassembly of the case.
1- The Legend is glued. So, you have first to use hoven to melt the glue before being able to do anything useful.
15min/ 60 degree in the oven. Or use an hair dryer (I used the former).
2- Don't forget to remove ALL the screws (even the one behind the IMEI notice).
3- Don't try to open the camera lid before loosening the glue or you'll damage the aluminium body.
4- You have to unplug all the différent cables, so take notes to remember where all of them goes.
5- You must disassemble all the boards. There are 2 boards. One supporting the sim / SD connector, and one supporting the screen/touchscreen.
6- When disassembling the screen board, remove it by pulling the touchscreen at the bottom, and lift it up. don't pass a tool on the sides to remove it or worse, under the touchscreen, you'r tool will touch the screen under and break it (like I did). The screen is very, very fragile
Now, I'm stuck here because I can't remove the connector of the legent which is passed under the shield on the back of the screen.
I'm not able to remove the screen so I would like to know how to remove this shielding or get back the touchscreen connector to be able to replace it.
Once I figure out how to remove this shiled, I may be able to remove the screen too.
But now, I'm clueless (it was 2 in the morning when I gave up).
Maybe, some of you knew the trick to open this phone further.
I'd like to hear about it.
A little up to my post for the ones who did not read it till the end:
I can't remove the connector of the legend which is goind under the shield on the back of the screen.
I would like to know how to remove this shielding or get back the touchscreen connector to be able to replace it.
Once I figure out how to remove this shield, I may be able to remove the screen too.
But now, I'm clueless (it was 2 in the morning when I gave up).
mate it sounds like you have trashed your phone.they are built NOT to be taken apart.They require special tools and process to be repaired. The only thing i would suggest is contacting your insurance company and let them know that your phone was crushed under a car or something and then crush it under the car and you can get it replaced. If you dont have insurance, take some out and make a claim in say a month or two.
Its not an honest thing to do but your phone sounds busted and its the cheapest way of replacing that handset.
Post a pic of it if you can
Unfortunately, I have no rights to post a link or some put some pics.
Something about spam and profile that should be reviewed before being able show any pics.
This device is glued. No specialized tools are able to open it without removing it.
That would mean that the phone cannot be repaired, only replaced. My phone's motherboard was replaced, so at the service stations they should have special tools.
Fixed it!
Bottom right hand corner:
Bend the shielding back just enough to allow you to slip the connector in & then use a little glue to stick it back.
Maybe I was lucky, but my phones working as good as new again
I fixed my Legend
Guys, I know it's been a while since you talked but in case someone else is looking for this info, that's what happened to me:
I cracked the display of my legend and purchased a new one on eBay (roughly 40 pounds) - obviously delivered from Hong Kong but a genuine Samsung (in case you didn't know the Legen's screen as well as most of the AMOLED screens are Samsung's).
Then I used the above information plus some YouTube videos to give myself an idea as to what should I do. The result follows:
I used a hair dryer to heat up the back of the phone (camera and loudspeaker cover). Perhaps I should have been more patient as in the end I decided to use a knife with a very thin blade to lift it and I scratched the plastic and the aluminium body a bit. Anyways - the back clicks in but is glued in addition to that so you have to use both the heat and gently applied force.
Once you remove the back cover (which took me the longest out of everything) you should start removing screws. There's two behind the back cover and six behind the bottom cover (where the battery is). At this stage you don't have to remove all the screws - the bottom two, the one behind the IMEI and the one under the VOID sticker hold the main board but the two screws sitting deeper inside the phone's body hold the front buttons so you may leave them for now.
Now comes the trickiest part so read carefully: the main board is held inside the unibody by the screws (which we already removed), but is also glued right below the camera lens and along the sides. You should probably heat it up as much as you can and for a long time. I decided to do it the hard way. My dislplay was already cracked and it's the most delicate part of the phone so I said "whatever" and used the same knife as before - moved it alongside the screen (pushed it in gently from the front) until there was no resistance (the glue let go). Then I pushed and I heated the thing up and pushed and tried from every angle until finally the board slid out of the unibody. I hope you'll find it easier then I did as it seems that everyone describing it found it quite doable.
Now everything becomes easy-peasy. Remove the remaining screws to put the buttons aside (you'll have both the actul buttons and the tiny board with sensors - the latter sticks to the screen but once you remove the connectors, yu can take it off too). All the connectors are quite easy to remove if you hav a needle or something (just pull them out gently). I didn't worry about noting which is which as ther is practically no way you can mix them up - they're very different.
The rubbery plastic black surrounding of the board clicks in, so once you find the right spots you can lift them gently and take the thing off. You'll be left with the display covered by the shielding from the top and a thin metal board from the bottom. You have to remove two more screws to disconnect the main display plug.
And the final bit (that's where the thread's author had a problem I believe). My display was cracked but the shielding - fine. These two are glued together so I had to find some space for my finger nail and lift the shield. By slowly and gently pulling it apart I detached one from the other - and had to do the same thing with the metal board. Don't forget there's some extra stuff to remove from the back of the display - they're all glued but the glue will remain fresh enough for you to glue them again - this time to the new screen. The same applies to the front shield. I hope you won't let any dust sit on it in the meantime. You should have a screen protector on your new display if you bought it like I did. Remove it now and the display will be happy to stick to the old front shield just as if it was always there. The metal back will also fit in.
Now you can go through the above process backwards - just remember to connect all the connectors.
What I didn't do: I didn't use ANY glue putting the phone back together. As an effect the front shield is sticking out a bit (doesn't sit in the unibody tightly). It doesn't affect the phone itself but it gives you the funny feeling that something isn't 100% right. But I prefer that than screwing something up with a misuse of glue (glue can be disobedient).
The most important piece of information: the phone is working 100% correctly as if it was never disassembled by an amateur. Apart from two scatches on the back, the VOID sticker missing, the front sticking out slightly (less than a mm) and the missing battery slider (which I forgot to put back in and didn't bother to repeat the whole process for the sake of it) - there is nothing wrong with the phone. So if you ever crack you ever crack your Legend's screen - you can try fixing it yourself if you have the courage.
I would like to see some photos too But I'm never gonna take my phone apart - can't see the point
Foto's
Nice thread, i myself am wondering, if a better gsm antenna can be fixed inside the phone. and connect them to the 2 connections.
Do you have any pictures of the inside housing etc?

[Q] Problems with a new touchscreen

Hey every body,
I have a big problem and hope someone who opened already a topaz can help me.
The Touchscreen of the Topaz broked, after the device fall an the floor, the display it self worked after that fine, so I decided to buy me a new digitizer.
The installation of that in the Topaz case worked very good, only the 4-pin connector for the digitizer cable didn't wont to do his work. Some black very small plastic "holder" part which seems to press some of the pins together, at the digitizer connector on the board didn't want to do what is his work.
I tried to press it back in but it didn't work. And now it jumped by pressing away, and I can't find it.
So this is how the story goes.
I hope some one have a Idea for this problem.
If I switch the device on the new digitizer don't work, so it seems that the plastic part is doing something.
It's only a way of put some pressure on the pins to ensure it's not falling apart whilst putting the phone back together. Just fold a paper to the right size and stick it in. Mind the side where you have to put it.

HTC Legend Screen (Digitizor) Replacement

I have looked high and low for Legend disassembly instructions in order to replace my screen (Digitizer) I finally found instructions on how to disassemble the HTC Legend and replace the screen thanks to allerien's post in the XDA forums 11th March 2011, 07:17 PM. There are no YouTube videos yet that I know of that actually show u how to remove and replace the screen so this is a step by step guide tat will help alot of user's including me.
Thanks Allerien
--------------------------------------------------------------------------------
I fixed my Legend
I cracked the display of my legend and purchased a new one on eBay (roughly 40 pounds) - obviously delivered from Hong Kong but a genuine Samsung (in case you didn't know the Legen's screen as well as most of the AMOLED screens are Samsung's).
Then I used the above information plus some YouTube videos to give myself an idea as to what should I do. The result follows:
I used a hair dryer to heat up the back of the phone (camera and loudspeaker cover). Perhaps I should have been more patient as in the end I decided to use a knife with a very thin blade to lift it and I scratched the plastic and the aluminium body a bit. Anyways - the back clicks in but is glued in addition to that so you have to use both the heat and gently applied force.
Once you remove the back cover (which took me the longest out of everything) you should start removing screws. There's two behind the back cover and six behind the bottom cover (where the battery is). At this stage you don't have to remove all the screws - the bottom two, the one behind the IMEI and the one under the VOID sticker hold the main board but the two screws sitting deeper inside the phone's body hold the front buttons so you may leave them for now.
Now comes the trickiest part so read carefully: the main board is held inside the unibody by the screws (which we already removed), but is also glued right below the camera lens and along the sides. You should probably heat it up as much as you can and for a long time. I decided to do it the hard way. My dislplay was already cracked and it's the most delicate part of the phone so I said "whatever" and used the same knife as before - moved it alongside the screen (pushed it in gently from the front) until there was no resistance (the glue let go). Then I pushed and I heated the thing up and pushed and tried from every angle until finally the board slid out of the unibody. I hope you'll find it easier then I did as it seems that everyone describing it found it quite doable.
Now everything becomes easy-peasy. Remove the remaining screws to put the buttons aside (you'll have both the actul buttons and the tiny board with sensors - the latter sticks to the screen but once you remove the connectors, yu can take it off too). All the connectors are quite easy to remove if you hav a needle or something (just pull them out gently). I didn't worry about noting which is which as ther is practically no way you can mix them up - they're very different.
The rubbery plastic black surrounding of the board clicks in, so once you find the right spots you can lift them gently and take the thing off. You'll be left with the display covered by the shielding from the top and a thin metal board from the bottom. You have to remove two more screws to disconnect the main display plug.
And the final bit (that's where the thread's author had a problem I believe). My display was cracked but the shielding - fine. These two are glued together so I had to find some space for my finger nail and lift the shield. By slowly and gently pulling it apart I detached one from the other - and had to do the same thing with the metal board. Don't forget there's some extra stuff to remove from the back of the display - they're all glued but the glue will remain fresh enough for you to glue them again - this time to the new screen. The same applies to the front shield. I hope you won't let any dust sit on it in the meantime. You should have a screen protector on your new display if you bought it like I did. Remove it now and the display will be happy to stick to the old front shield just as if it was always there. The metal back will also fit in.
Now you can go through the above process backwards - just remember to connect all the connectors.
What I didn't do: I didn't use ANY glue putting the phone back together. As an effect the front shield is sticking out a bit (doesn't sit in the unibody tightly). It doesn't affect the phone itself but it gives you the funny feeling that something isn't 100% right. But I prefer that than screwing something up with a misuse of glue (glue can be disobedient).
The most important piece of information: the phone is working 100% correctly as if it was never disassembled by an amateur. Apart from two scatches on the back, the VOID sticker missing, the front sticking out slightly (less than a mm) and the missing battery slider (which I forgot to put back in and didn't bother to repeat the whole process for the sake of it) - there is nothing wrong with the phone. So if you ever crack you ever crack your Legend's screen - you can try fixing it yourself if you have the courage.
Isn't it possible to just exchange the glass along with with the digitizer? I myself need to replace the digitizer, because mine went quite unusable after an accident with water..
Either way this was a nice guide which i will make use of!
great info my legend has only a broken digitizer so i will be replacing that soon

[Q] Phantom touches/unresponsive touch screen - only when the back cover is on

So I've been using my N7 on and off since I bought it in January. I would've used it more if it wasn't for the fact that the touchscreen responded really bad to touch and freaked out every now and then. It even almost bought an app on its own in the play store once. As I bought it through a retailer in another country I figured I would try to fix the problem myself - and I did kind of.
I tried a lot of things that people suggested in other threads here on xda, reddit, youtube, etc. but the only thing that seemed to work somewhat was tightening the screws around the edges after opening it up. The problem still persisted to some degree and got worse again after a few weeks.
After opening it up again a few weeks ago to fiddle around with the screws again I realized something - the phantom touch problem was gone and the screen had perfect response whenever I was handling it with the back cover off. So I put it in a case without putting the cover on first and I've been using it like that ever since - this leaves the wifi/gps/etc. without a grounding connection though, and I also prefer to use it without a case so my question is this:
Has anyone had the back cover apply pressure/mess with the touch screen in any way?
I have no screen lift at all, but these are the methods I have tried:
Tightening screws(worked somewhat)
Loosening screws(didn't work)
Putting a small piece of paper between the black cable that apparently connects the touch screen and the circuit board in case it was causing a short there due to pressure or something(didn't work)
Additional info: Whenever I remove the back cover, the only place where I have to apply some extra pressure to get it loose is right around where the aforementioned black cable is.
erikkr said:
So I've been using my N7 on and off since I bought it in January. I would've used it more if it wasn't for the fact that the touchscreen responded really bad to touch and freaked out every now and then. It even almost bought an app on its own in the play store once. As I bought it through a retailer in another country I figured I would try to fix the problem myself - and I did kind of.
I tried a lot of things that people suggested in other threads here on xda, reddit, youtube, etc. but the only thing that seemed to work somewhat was tightening the screws around the edges after opening it up. The problem still persisted to some degree and got worse again after a few weeks.
After opening it up again a few weeks ago to fiddle around with the screws again I realized something - the phantom touch problem was gone and the screen had perfect response whenever I was handling it with the back cover off. So I put it in a case without putting the cover on first and I've been using it like that ever since - this leaves the wifi/gps/etc. without a grounding connection though, and I also prefer to use it without a case so my question is this:
Has anyone had the back cover apply pressure/mess with the touch screen in any way?
I have no screen lift at all, but these are the methods I have tried:
Tightening screws(worked somewhat)
Loosening screws(didn't work)
Putting a small piece of paper between the black cable that apparently connects the touch screen and the circuit board in case it was causing a short there due to pressure or something(didn't work)
Additional info: Whenever I remove the back cover, the only place where I have to apply some extra pressure to get it loose is right around where the aforementioned black cable is.
Click to expand...
Click to collapse
Hmm, have you checked the N7 under a florescent tube light? You should try to view the light's reflection on the n7's screen. It should be 'mirrored perfectly'. If the reflection of the light is crooked/bent, this means your screen is no longer flat. Ie. A flat mirror should show your reflection as it is. A curved mirror will distort the reflection.
If the screen is heavily distorted, this could mean the touch sensors are also 'bent' and touching the screen internals.
Check the reflection with cover on, and also cover off.
If with the cover off the n7, the screen seems to be 'flatter'. Then we could conclude the screen is fatigued by stress somehow by the attachment of the covers. If it somewhat same, then the problem is something else.
Since the cover provides ground points for the n7 circuit and it's antennas, maybe you should try cleaning the contact points on the cover side. There should be grooves made by the contact pins from the n7 on the cover, over time they might oxidize and cause a short circuit.
It is possible the touch mechanism is not being properly grounded somehow.
PLEASE BE EXTREMELY CAREFUL if you are going to clean the contact pins on the n7 side, they are small and very brittle.
Try to see if anything on the cover is touching the circuit board or creating a short circuit somewhere when installed.
These are the 2 causes i can think of. I had this problem too, i loosen some screws and re-check under a florescent light to see it's reflection, and i re-loosen or tighten until the reflection is nearly perfect (screen should be flat and reflecting like a mirror), if not it is bent by stress from screws being too tight or loose at some points.
Then i also cleaned the contact points and pressed the aluminum 'heatsinks' on the n7 side to make sure they dont contact anything else. I did both the same time, following by a switch in ROM and Kernel. So i'm not sure which actually helped. I'm sure i took some stress off the screen by the reflection thing. The grounding also makes sense as an intermittent ground causes stuff to f-up (my car) lol. But you may try n see how it goes. Cheers.

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