Common Touchscreen Problems


Probably the common problem of all the modern gadgets is touchscreen malfunctioning regardless whether in smartphone, tablet PC or any touch input device.
Today it is easier to buy electronics maintenance tools than ever before. Once service centers were monopolists in touchscreen repairs because they were the only ones who possessed appropriate set of tools and instruments. However, now, anyone can buy special tools through the web. If you have decided to repair a touchscreen, either commercially or just of your own gadget – this article is for you.

Choosing a touchscreen you must carefully select its model and series. Make sure the chosen touchscreen is compatible with your device. First of all, please pay attention to the dimensions and the placement of the sensor and the camera windows as well as the loudspeaker vents. Any differences may undermine the device's proper functioning. Especially, this caution applies to China-made devices. For example,

Touchscreen Removal

Make sure you have enough knowledge and skills to carry out properly all the following operations without damaging your touchscreen. In order to remove the touchscreen from your device, you either have to be extremely neat-handed or just own special device for removing the touchscreens. While disassembling your gadget, you have to remember or record (make photos of) complete consequence of your actions and location of the units you're about to disconnect. You can find all the necessary tools here.

Any device has components requiring careful handling, for example, flat cables, power buttons, side locks, antenna, etc. While unlocking the device's casing, please, take proper care to avoid damaging the electronic components mounted close to the edges of the device.

After all the units that prevent accessing the touchscreen are disconnected, you can start removing the touchscreen. There are two approaches of manufacturers to the touchscreen mounting – the monolith (jointless) and the separate.

There are, also, modular (undismountable) touchscreen models and other touchscreens that require extra efforts for their removing. A touchscreen is, usually, connected to the motherboard with a flat cable or with special terminal. If the touchscreen is connected with a flat cable, please ensure safe removing of the cable to avoid damaging it.

If the touchscreen is connected through the terminal, its contacts simply touch special receiver on the motherboard, thus allowing easy and safe removal of the touchscreen.

If your device has the sensor and the touchscreen assembled together with photopolymer glue, we recommend using special touchscreen glass separator.

We have made special video manual on how to properly use such separator.

Remember, before using the separator, you will also need:

Installation of the touchscreen will require using special glue that bonds under UV light. Our video brings some light on choosing the right glue.

Use LCD module holder and UV drying lamp to make the glass stick on the glue.

Some models provide easier way of the touchscreen replacement. These models have the touchscreen attached to the front panel with a double-sided tape.

Such double-sided tape may be removed by any thin blade with flat surface. In case the glue holds stronger than expected, try preheating the glued surface with hot air soldering iron. Heat up the surface carefully in order to avoid damaging the plastic frame.

Touchscreen Selection

Now, after you have finally disassembled your gadget, it's the time to choose the touchscreen. The key characteristics shall be the version and the model marking of a touchscreen.
Looking for the proper touchscreen, you may have to consider the thickness of the double-sided tape that the screen shall be mounted with. If the tape appears to be too thick, the installed touchscreen shall protrude out of the device's frame. Otherwise, if the tape is too thin, the installed touchscreen shall be placed below the frame that will cause malfunctioning. Also, you may try sticking on the thin tape in layers to reach the optimal result. Note! For particular devices it is critically important to avoid contact of the touchscreen with LCD or metallic casing.

By the way, you may find the appropriate double-sided tape in our store. Nonetheless, every component we describe herein may be found in our store too. Should you have any questions, please reach out for Technical Support Service. Our staff is ready to help you choose everything you need.

Touchscreen Replacement Procedure

Finally, after you have all the necessary tools and materials, you can start the replacement.

Before the installation (sticking) always perform the touchscreen operation tests!

Therefore, you will avoid installation of the faulty touchscreen and save extra costs from buying another touchscreen model. We provide the warranty for every touchscreen sold in our store. More details about the warranty you shall find on the Warranty page.

If touchscreen is not working straight out of a box, this does not mean the touchscreen is faulty. Check if the touchscreen is installed correctly and it does not touch the LCD. This is critically important! Then inspect the touchscreen contacts installation. Remember that the contacts on the flat cable and the touchscreen slot shall not be cleaned with any metal instrument, use piece of rubber instead.

After making sure that the connection is fixed properly, move on to the software tuning of the new touchscreen.
It is important to update the touchscreen data. Firstly, you should turn on the device with the touchscreen disconnected. During the boot process, the system shall clear the controller settings. After that, the system shall start. Then, your next steps are:
Without turning the device on, remove the battery→connect the sensor→turn on the device→sensor software shall be updated.

The abovementioned procedure is called touchscreen calibration. The calibration is also used to remove the sensor's response problems, the sensor's super-sensitivity or the sensor's poor sensitivity. The calibration shall be performed with a special software that you can download from the web.

In some cases it is necessary to flash the gadget's firmware – change the device's firmware, update the firmware or downgrade it. If that is the case, you can either ask professionals or experiment on your own with various firmware versions.

Sometimes you do not have to flash the device, but you have to perform the HARD RESET procedure. The HARD RESET procedure is individual for each device model and the resetting algorithm may be found on the web.

Please note! All the changes made to the OEM firmware of the device may cause personal data loss or void the warranty. If you understand the risks, but, anyway, want to flash the firmware, please make the backup of the phonebook, personal notes, photos, videos and the rest of the information important to you.

Shall the broken touchscreen prevent you from starting the information backup, you can do it via PC connection using special OTG cable.

Sometimes it may be necessary to perform the procedures in a certain consequence, for example, flash the device's firmware firstly and, then, calibrate the touchscreen.

If none of the above helped, the old broken touchscreen is not working and the new one too, there is another method to test the operation of the new touchscreen.

In some cases, the controller soldered on the flat cable may appear incompatible with your device model (especially in China-made tablets). If you have relevant experience and qualification to repair, you may braze out the old controller out of the broken sensor and sold it on the new one. If you consider a possibility to return the component, please bring this matter in advance with your manager in our store. Bad soldering may void the warranty for the complete touchscreen unit.

There is the protective seal attached to the rear side of a touchscreen that shall be removed only after the complete performance test.

Hope you will make the installation perfectly and your touchscreen will operate smoothly.

If you have performed everything correctly, according to the given instructions, and the new touchscreen fails to work, you shall have the right to return the touchscreen to the store (in case the warranty requirements are complied with). More detailed information about the return procedure with respect to the touchscreens purchased from our store, you may find at the web-page

GsmServer Store wishes you have your gadget safe and secure, but, whatever the case may be, we will do our best to find all you need. Good Luck!