[ iPhone 4 ] Touchscreen not working after reassembly

jobertomeu Posted messages 1289 Status Member -
gouessax - 16 Jul 2017 at 07:04

Hello,
So here it is, I ordered a complete screen on eBay, after receiving it, I assemble it, as I usually do. I turn on the iPhone, the display works, but the touch doesn't. I send an email to the eBay seller, they send me a new one, I just received it today, I assemble it, it works, I realize that I forgot to replace the grille for the speakers, so I disassemble it, put the grille on, and reassemble it, I turn it on and again, the touch doesn't work .. Everything is well connected, the touch ribbon is properly plugged in. I've probably done this operation more than 20 times on an iPhone 4, I've never encountered this problem ..
If you could help me ..
Thank you! :)

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8 answers

Answer 1 / 8

Best answer
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Raph22

An important thing to know that a charming iPhone screen saleswoman told me: you need to heat the connectors if the contact is poor.
That's what I just did with exactly the same symptoms described in this post: new screen, but the touch doesn’t work, and even the LCD seems to fail with insistence...
I did a first pass with a hairdryer, 30 seconds 10 cm away from the connectors, moving it back and forth.
I then noticed after reconnecting that a faint Apple logo appeared!
I heated it again, this time with a bit more heat and airflow: perfect result!!!! The LCD and the touch worked.
35
1. dydoudu38 Posted messages 1 Status Member
  
  I just did what you described, but nothing works; my screen + LCD is new, but it's still BUGGING :/
  WAITING FOR A RESPONSE
  
  0
  1. Raph22 > dydoudu38 Posted messages 1 Status Member
    
    Have you seen the beginning of an image appear with the new screen? If so, then the "blow" from the hairdryer can help soften the contacts and resolder them.
    If you didn't see anything on the screen, try with your old screen if you still have it: it's better to properly diagnose the situation rather than assume a defect with the new part like the screen.
    
    0
Answer 2 / 8
lou71

Hi.
Hypothesis 1: When lifting the screen, you did not place the touch ribbon cable correctly, which slightly tore it.
Hypothesis 2: The connector on the motherboard is faulty.
17
1. Tito
  
  Is it possible to change the nap?
  
  -1
Answer 3 / 8
Arriman Posted messages 8 Status Member 8

Have you tried to remove the "speaker grille"
If so, does it work?
If yes and no: try without the grille with the other screen. With and without "speaker grille".
4
Answer 4 / 8
Gégé120698

I have the same problem. Could it come from the new screen I bought (the complete kit) since we've redone everything three times and nothing?
4
Answer 5 / 8
Lorinesrv Posted messages 1 Status Member 4

Hello, like you, I'm having a problem with my iPhone 5. My screen was broken, so my dad changed it for me, and everything was working. One morning, someone called me, and I couldn’t hear the person’s voice unless I used the speakerphone, so I asked my dad to open my iPhone to take a look. There were no visual issues regarding the sound problems, and when he put it back together, I tried to unlock it, but my touch screen wasn't working anymore. It's not the screen because it works on another iPhone 5. So now I can't retrieve my iPhone, I have a sound problem when someone calls me, and the touch screen isn't working. Do you know what the problem might be and how much it would cost me (just for the touch screen)? Thank you in advance.
4
1. Gégé120698
  
  Good evening,
  When I reassembled my screen, the touch function was not working, so I asked for a screen exchange, and upon reassembling the broken one, the touch was working, so I think the problem comes from your screen! And not from your phone, everything was properly put back in place?
  
  0
2. gouessax
  
  Sun, July 16, 2017 05:40
  
  Hello,
  
  I'm responding even if the topic is old...
  For those who follow!!! ;-)
  
  A little tip that I encounter regularly... :-)
  
  At the time of the change, I want to say, "personal"... :-): from the screen, the most widespread problem is the lack of "care" during disassembly and reassembly...
  
  Touch screens (especially capacitive ones) do not tolerate any alteration of the surface state inside the panel.. (fingerprints, glue residues, dust, scratches, etc...).
  
  Explanation:
  This disrupts operation because most of the time, these dirty spots send the message, through magnetic, static action, and others..., that one or more fingers are already positioned in a fixed and permanent way.. at least.. the device understands it that way...
  So...
  If an entire area is very dirty, or even just a little sometimes... depending on the sensitivity of the touchscreen...... the device may consider that there are, 1, 2, 10, 20, or even 100 fingers already positioned.. adding one "real" finger, even if it moves... therefore has no impact since all touch screens have a defined number of possible contacts.. whether they are fixed or moving... and these possibilities are all already used...
  
  It's easy to demonstrate with a viable device having few possible touch points... position the maximum number of fixed contacts, and add one more later... the last one will not make the device work...
  
  So:
  The first thing to do,..., of course, after checking the connections and the proper positioning of sometimes tricky ribbons... :roll:
  
  1/ Carefully check the surface condition of the inside of the touchscreen...
  clean meticulously ...
  If needed,... in case of glue residues... use pure acetone...
  But be careful..!! Highly corrosive product... so...
  Do not scrub... nor linger too long... nor with an aggressive cloth or sponge... (a soft paper towel or a tissue soaked will be best..) to avoid damaging the surface ... with light movement, and always in the same direction..., without touching the other plastic parts, as they are not of the same resistance... they risk being significantly damaged....
  Then use a glass cleaning wipe, and wipe until all visible traces disappear in the light, with a soft non-static cotton cloth.
  
  Warning:
  "All" the area located within the frame defined by the electronics of the touchscreen must be clean!! Not just the transparent part...
  
  2/ Check that there is no protective film not removed... (ridiculous.. we agree.. but I have experienced this in after-sales service.. so... I'm saying it..) :shock: .
  
  3/ Center the LCD screen well, being careful not to "re-dirt" the inside of the touchscreen while positioning it... (double-sided adhesive glue...)
  
  4/ Check that the LCD screen cannot move.. (sometimes the housings differ, and are slightly larger than the size of the LCD.. so they will need to be shimmed to prevent them from moving and dirtying the important part of the touchscreen with glue residues..
  
  That's it... If despite this, the screen still doesn't work.. consult a professional..
  
  Best regards.
  
  0
Answer 6 / 8
jobertomeu Posted messages 1289 Status Member 86

Up? I recommended another screen, the touchscreen still doesn't work, I restored it, still doesn't work... I don’t know what to do anymore...
1
1. Pierrot-du-18 Posted messages 147 Status Member 5
  
  It might be an internal issue; in that case, you would need to buy a whole tablecloth (don't worry, it's not that expensive).
  
  0
2. jobertomeu Posted messages 1289 Status Member 86
  
  An internal problem? Hmm, I have my screen which is new and works on another iPhone that connects to the motherboard of the other iPhone.. I think it's the touch on the motherboard that has burned out, that's all.. I'm going to get myself another motherboard, great..
  
  0
3. Pierrot-du-18 Posted messages 147 Status Member 5
  
  Yes, it's therefore an "internal" problem with the phone, as I was saying: whatever screen you use, it won't work because the problem is at the level of the phone itself... The question remains whether to buy a new ribbon cable or a new motherboard altogether...
  
  0
4. jobertomeu Posted messages 1289 Status Member 86
  
  I don't understand what you mean by "buying a tablecloth" ..? Are you talking about the FPC connector?
  
  0
5. Pierrot-du-18 Posted messages 147 Status Member 5
  
  A ribbon cable is the set of electrical circuits (not components) specific to a region of the iPhone: there is therefore a ribbon cable for sound, another for the camera... The purpose is to connect the component to the motherboard.
  
  0
Answer 7 / 8
jobertomeu Posted messages 1289 Status Member 86

No, nothing works, I tried putting another screen from an iPhone 4, it works, but the touchscreen still does not work.. When I put the newly received screen on another iPhone 4, it works perfectly..
What to do?
0
1. iphonetoupour
  
  I had the same problem! It's the motherboard connector that is faulty.
  
  0
Answer 8 / 8
Pierrot-du-18 Posted messages 147 Status Member 5

It might be because the screen you bought doesn't work.
-1

[ iPhone 4 ] Touchscreen not working after reassembly

8 answers

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