August 15, 2022

How to diagnose and repair a broken display on an iPhone?

You may know this, just an unfortunate crash and your iPhone has a broken screen. The consequences can vary, from cracked glass to stripes to a cracked contact layer. In this article, we will discuss the specific defects that can occur when the display is mechanically damaged and explain what they are specifically causing and how to fix them.

First, let’s look at a detailed analysis of the composition of the display. The upper part of the display is made of glass, which serves as protection and at the same time an area for interaction with the display. The glass is very thin, but it is hardened to withstand even minor impacts. The glass is attached with a layer of a special transparent glue (also known as OCA – optically clear adhesive), which is pressed onto the display, using a press placed in a vacuum chamber. Thanks to this procedure, the glue perfectly fills the space between the glass and the contact layer, no bubbles are formed in it and perfect transparency is maintained. The touch layer or digitizer has a touch sensing function so that it is possible to control the phone using the display. It is one of the most fragile parts of the display and therefore is often damaged when the phone is dropped. Digitizer is so accurate that it can detect touch at the same time in several different places and with an accuracy of up to one millimeter. The next layer is the polarizing filter, which makes the image on the display visible to the human eye. The next part is the LCD display, which consists of two plates, between which are liquid crystals that reflect light. The penultimate layer is a backlight formed by a layer of LEDs, which act as a light source for crystals. Thanks to this layer, the image is clear and sharp. Newer models that have an AMOLED display no longer apply this layer. The last layer is seznzory. This layer was not installed until the arrival of the 3D touch function on the iPhone 6s. Its only function is to sense the force of the pressure with maximum accuracy. which makes the image on the display visible to the human eye. The next part is the LCD display, which consists of two plates, between which are liquid crystals that reflect light. The penultimate layer is a backlight formed by a layer of LEDs, which act as a light source for crystals. Thanks to this layer, the image is clear and sharp. Newer models that have an AMOLED display no longer apply this layer. The last layer is seznzory. This layer was not installed until the arrival of the 3D touch function on the iPhone 6s. Its only function is to sense the force of the pressure with maximum accuracy. which makes the image on the display visible to the human eye. The next part is the LCD display, which consists of two plates, between which are liquid crystals that reflect light. The penultimate layer is a backlight formed by a layer of LEDs, which act as a light source for crystals. Thanks to this layer, the image is clear and sharp. Newer models that have an AMOLED display no longer apply this layer. The last layer is seznzory. This layer was not installed until the arrival of the 3D touch function on the iPhone 6s. Its only function is to sense the force of the pressure with maximum accuracy. Newer models that have an AMOLED display no longer apply this layer. The last layer is seznzory. This layer was not installed until the arrival of the 3D touch function on the iPhone 6s. Its only function is to sense the force of the pressure with maximum accuracy. Newer models that have an AMOLED display no longer apply this layer. The last layer is seznzory. This layer was not installed until the arrival of the 3D touch function on the iPhone 6s. Its only function is to sense the force of the pressure with maximum accuracy.

In addition, components such as a plastic mounting frame, a dust protection grille and plastic mounting components for flex cables, cameras and sensors are installed as standard on the displays. The frame is glued directly to the display glass, which extends beyond the other layers. The frame contains plastic protrusions on the top that slide into the back cover during installation, metal protrusions that slide between the clamps on the sides of the cover and 2 screw holes that hold the frame and with it the display firmly attached to the phone body.

What problems can occur after a phone crash?

Broken glass

Cracked glass, or classic spider, is the most common display defect after the fall of the iPhone. This is the rupture of the uppermost part of the front panel. Over time, the cracks widen across the display and can even cut easily during operation.

Repair:

  1. The first method is to use LOCA (Liquid optically clear adhesive), which is a liquid transparent adhesive that dries after being irradiated with a UV bulb. The application of this glue does not require any special equipment, but it is a procedure for manually skilled individuals. All you have to do is cut the glass, clean it of the glue (at this stage, small scratches usually form on the polarizer, so you need to be extremely careful), apply the glue, glue the glass and replace the backlight. Due to the fact that the glue is liquid, it is also poured into small scratches, which are formed on the polarizer and the contact layer, as a result of cleaning from the glue and thus no visible bubbles are formed. A strong disadvantage is that the adhesive is poured during application even under the backlight of the display, which is located in the back of the display, but overlaps the other parts in the sides. The backlight also needs to be replaced, and micro soldering and soldering experience are needed, as well as the choice of a quality backlight that will not make glowing semicircles at the top of the display. Another disadvantage is the fact that the glue often starts to turn yellow over time and the whole process needs to be repeated. This method is used by most services, especially because there is no need to buy very expensive equipment.


  2. The second method is to use OCA (Optically clear adhesive) glue. This glue is not liquid, but it is a solid plate that glues on both sides precisely glues new glass. However, the application of this adhesive requires professional equipment and expertise with this type of repair. The procedure is partly similar to the previous method, first the glass is cut and the glue is cleaned, but then it is also necessary to cut the polarizer, otherwise scratches and bubbles would be visible on the display. After removing the polarizer, it is necessary to apply a new one and then glue and glass. The application takes place under the power of a special press, which is placed in a vacuum chamber, where a specific temperature is maintained. The remaining bubbles in the overpressure chamber are then removed. The disadvantage of this method is that bubbles may reappear on the display later and the sensitivity of the touch layer is reduced.


  3. The third and easiest method is to replace the entire display with a new one. The iPhone will be like new again and you can handle the repair yourself. The big advantage in this case is, in addition to the speed and ease of repair, also the service life of the display, which is, due to the use of a completely new piece, significantly longer.

Bars on the display

The streaks on the iPhone display, which are usually accompanied by a slight graying, are caused by a problem with the flex cable that connects the display to the system board. In practice, the connection in the flex cable, the flex cable connection at the display, the cable from the motherboard or the connector from the motherboard may be broken. However, this problem is most often caused by the connector snapping off the system board. To find out the cause, it is necessary to disassemble the phone and examine the flex cable. Streaks on the display may also appear when installing a new display if some dirt gets on the pins in the connector. 

Repair:

In the event of a damaged flex cable connection and a broken connector or flex cable connection on the display, the only solution is to completely replace the entire display with a new front panel. The repair is quick and you can handle it yourself.

If the flex cable is knocked out or there is just dirt in it, you are lucky and all you have to do is disconnect the flex cable, clean it and reconnect it.

Cracked touch layer

If iPhone doesn’t respond to touch, the touch layer is damaged. Unfortunately, this problem cannot be solved as in the case of cracked glass and the entire display needs to be replaced.

If your iPhone has any of thesdee defects that require replacement of the display, do not hesitate and order our set of displays with tools , thanks to which you can repair the iPhone yourself.

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