What to do if the phone backlight goes out? Sony xperia z1 display backlight fuse.

There are many little things that we don’t even pay attention to that affect our comfort in life. And a change in usual conditions can sometimes become not only a big surprise, but also a problem. For example, the backlight of the phone. While the device operates in the usual way, it is unlikely that a person will think about how its disappearance could affect the operation of the device and personal comfort. However, at one moment it may disappear, bringing unusual discomfort.

So, what to do if the phone’s backlight goes out? If standard user manipulations with turning on and off, removing the battery and restarting the device do not bring desired result, don't panic. Most phone owners needlessly get scared and think that it’s time to replace the display, without thinking about the feasibility of this procedure.

Display backlight key failure

The reason for the disappearance of the backlight does not necessarily have to be serious, due to moisture or flying onto the floor from a height. One of the most common causes of problems with the backlight is a breakdown of the display backlight key (the transistor in the display backlight power circuit that ensures its operation) and in order for everything to return to normal, it is necessary to replace this spare part.

After this it will be necessary to perform a complete replacement software mobile device. It is impossible to bypass this procedure, because after replacement there will be a need to configure the parameters of the power controller that supplies voltage to the transistor. Therefore, you should take care in advance about saving important data stored on your phone - otherwise, it will be lost forever. Considering this fact, before contacting the service center, be sure to do backup copy the necessary data.

Driver assembly failure

The second probable reason for the disappearance of the backlight is in the driver microassembly. Self-updating is strictly not recommended, because there is a high probability that an inexperienced user will simply kill the gadget, only aggravating the problem.

It should be remembered that any problem with the backlight (it turns on spontaneously, goes out too quickly) may indicate that it may soon go out. If you notice something strange in the behavior of your unit, do not delay and immediately contact the service center. In some cases, it will even help you save money.

The third reason why the backlight may disappear is very trivial and common. These are trivial problems with the latch of the display connector. Sometimes it’s enough just to tighten the latch of the display connector well and the mobile device will work as it should again. Sometimes it is necessary to replace a loose connector or thicken the display cable to ensure normal contact.

And, of course, we cannot help but say once again that the backlight, of course, can disappear due to a fall or the formation of condensation due to moisture. In fact, problems associated with the disappearance of the backlight after such incidents (if the display is not broken, of course) can be classified as follows:

• There is no backlight, but there is an image - most likely, the problem is in the backlight driver or in the coils.
• There is no backlight or image - there may be a problem with the processor.

Remember that only a qualified technician can accurately diagnose problems. Independent attempts to make a “diagnosis” mobile device or try to estimate the scope of renovation repairs will most likely not lead you to a constructive result.

Everyday use and physical damage to a mobile gadget necessitate repair of the screen backlight circuits Sony smartphone. The cause of the breakdown can be either strong falls or impacts, falling into water, voltage discharges, or a tiny grain of sand from the beach that has pushed through the screen cable and reached the bindings of coils, diodes, capacitors and transistors, connectors and resistors, etc. Let's look at in the article:

• Signs of malfunction;
• Tools and materials;
• Repair process;
• Guarantees.

Symptoms of a problem

If there are burnt-out components in the display backlight circuits on a Sony smartphone, the screen will remain black when turned on. However, this failure does not affect the operation of the operating system and applications. The mobile device will still boot, spin the screensaver, display a menu, and open the software. In other words, if you hear that the device is working, but this is not visible from the outside, then diagnostics and restoration of the power circuit in the SC is required.

Tools and materials

To diagnose the power supply circuit of a Sony smartphone, an engineer Service center uses a multimeter. With its help, each harness microchip that is suspected of burning out is called. Restoration will require soldering stations of various calibers. To disassemble the gadget - binocular microscopes, plastic spoons, screwdrivers and tweezers. To remove dust and contaminants, craftsmen use disinfectant compounds for stains; for soldering, they use flux-gel and braids, and solder.

Repair process

Repairing screen backlight circuits means resoldering contacts or elements of a Sony smartphone microcircuit. For this master Service center disassembles the device.

The elements responsible for backlighting the smartphone screen are located on the motherboard. They are very small and tightly adjacent to each other. And if you consider that we are talking about telephone microcircuits, you can imagine how exquisite the work of a master must be. Most often, the problem is a burnt-out voltage microchip - a choke or diode.

To get to the microchips, the engineer carefully releases motherboard and places it under the soldering station. The contacts of the inductor and diode are so small that you can’t do without a microscope. When soldering, it is important to monitor the temperature. The chip heats up at 300 degrees. The soldering station allows you to use special program regulate air heating and attach a protective cap to surrounding components, preventing them from accidental heating.

After dismantling the burnt parts, the engineer solders new elements to the board. Then he starts assembling the phone. Upon completion of work, the readiness of the device is checked by the Sony Quality Control Department. Once the repair goal is achieved, the updated smartphone is returned to the client.

Guarantees

The service center provides a guarantee for the repair of Sony smartphone screen backlight circuits. Desoldering, soldering and restoring the damaged link of the backlight circuit is a jeweler's work, because one wrong movement can lead to damage to nearby components printed circuit board and completely break the gadget. Therefore, engineers undergo special training and knowledge testing according to international standards. The guarantee for their services is up to 3 years.

Sometimes craftsmen from neighboring workshops turn to me for help.

The technician replaced a touchscreen with broken glass on a Sony Xperia Tablet Z2 with a new one; accordingly, he delaminated the SGP511 SGP512 SGP521 SGP541 (MDK MB-17 W 94V-0) brand module from the old touchscreen, prepared it and began testing and installing and gluing the new one.

But something went wrong...

After a grueling job of unsticking broken glass from the Tablet Z2 module, the master was very tired and was not attentive. He connected a display to the device and... the backlight on the tablet burned out, so smoke began to appear.

The backlight has disappeared, and on xperia phones and tablets it usually burns out if you do not unfasten the battery and “hotly” attach and unfasten the display cable to the motherboard. But according to our neighbor’s repairman, the battery was disconnected from the motherboard.

Most likely, the technician did not insert the display cable all the way, so the contacts from the two rows were shorted together.

The generator is responsible for the lighting. It includes the basics - a microcircuit, a coil and a diode.

We check the zero resistor (the so-called fuse through which the microcircuit is powered - it has burned out.

You can close it with a jumper, or replace it, but the question arises, if not only it burns out, what will happen when you jump it? It's simple. If the microcircuit burns out, then with a bridged fuse it will get very hot. If the coil burns out, the appropriate voltage simply will not be generated. If there is an open circuit in the coil, the output of the generator will most likely be 0 volts; if there is an interturn short circuit in the coil, the output will be at least 4.2 volts. The diode usually burns out along with the microcircuit.

We close the fuse and check - the backlight is working, but there is no image.

Check the power on the display board (resistor to the left of the socket) = 4 volts.

This means there is a voltage drop across the burnt resistor on the motherboard.

The track burned out along with the resistor. We put another resistor and solder the wires instead of soldering them to the tracks. The image appeared.

The main work has been done. Now our neighbor's repairman just needs to replace the zero resistor and glue the touchscreen.