In detail: do-it-yourself repair of samsung led TVs at the top is a strip from a real master for the site my.housecope.com.
Samsung has long been one of the most popular brands sold and serviced in Russia.
The choice of buyers is justified by the favorable price-quality ratio of the equipment, and the popularity among repairmen is due to many factors that determine the simplicity and ease of repair and maintenance.
Despite the variety of models, Samsung TVs for technicians and service engineers remain uncomplicated and predictable in repair, and the manufacturer's timely technical support with components, modules, documentation and software greatly facilitates and simplifies diagnostics and repairs.
Since the beginning of the nineties of the last century, the craftsmen have accumulated rich experience in repairing Samsung TVs, which was discussed and preserved on the Internet in numerous conferences and blogs of repairmen.
Typical defects of some models sometimes caused controversy and deserve special attention in considering the causes of malfunctions and methods of their elimination.
In this series of articles, it is planned to consider the most common malfunctions of Samsung CRT TVs from 2000 and the most popular LCD TV models in the repair practice.
There is no need to consider the problem of electrolytic capacitors in the rectifier filters of power supply modules, since this is a massive trend characteristic of the first generation of LCD TVs. It should be noted that in LED TVs, the problem with electrolytic capacitors is less common. Perhaps this is due to the lower consumption of LED backlight power converters.
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Operation of some first generation Samsung LCD TV models with defective power filter capacitors may cause software failure. At first, the settings for the channels may disappear, sometimes specific distortions appear in the “Cinema” mode, the screen backlight adjustment may not work correctly.
Often there is a complete failure in the software and the TV is no longer included in the operating mode.
In such cases, after repairing the power module, it is necessary to replace the contents of the EEPROM memory.
One of the most popular power supplies in repair is described separately in the article Typical faults BN44-00192A. In addition to defects caused by a malfunction of electrolytic capacitors, we note two more typical malfunctions of this module. Ring cracks in the soldering of the terminals of the switch-on transistor from standby mode, as well as breakdown of the sealant with subsequent short circuit and damage to the 2200pF capacitor and breakage of the 0.22 Ohm resistor in the power supply circuit of the key transistors of the converter.
Noise in the image in the form of curved oblique stripes associated with poor filtering of the tuner's power supply is eliminated by replacing the 100uF 16V capacitor on the main board. In this case, there is no need to change the capacitor in the tuner. Sometimes the masters do the opposite, due to insufficient competence, then such a replacement will help for a short while.
Another popular typical malfunction of some Samsung LCD models is the use of the AS-15 gamma correction chip in the T-CON board. AS19. The defect is associated with distortion of color transitions. The image becomes lighter and in places looks like a negative.
The latest LCD models, SMART-TV in particular, have problems with BGA soldering technology for highly integrated chips.In such cases, malfunctions may occur, usually manifested with warming up, which are caused by a violation of the contact of the chip pins with the corresponding pads on the board.
The malfunction of the LCD matrices is perhaps a separate topic for discussion, but it makes sense to briefly consider some of the external manifestations of its defects.
In most cases, these are straight vertical stripes in certain areas of the screen or throughout its entire area. Stripes can be different, both colored and black and white of different thickness.
Sometimes the nature of the stripes changes with external mechanical stress. Freeze-frame images may appear.
Such matrix defects are associated with broken contacts in the connections of the loops, which can sometimes be restored with warming up.
Repair of the matrix in such cases is associated with its disassembly and restoration of contacts in loops or duplication of connections with external conductors - a complicated process, not recommended by manufacturers and may not always be a successful and reliable solution to the problem.
Due to the fact that the price of the matrix is quite high, accounting for more than half of the cost of a TV, in most cases, owners of post-warranty TVs refuse to replace the matrix due to the economic inexpediency of repair.
In many models of LED TVs of the 5 series, panels (matrices) with backlight LEDs of sufficiently low quality are installed, or the current in the LEDs is incorrectly calculated. This currently popular typical defect can manifest itself already in the first year of operation. In this case, there is simply no picture.
In authorized service centers, on the recommendation of the manufacturer, they change the LED rulers and limit the current in the LED drivers so that the TVs work out at least the warranty period. And in post-warranty cases, this problem is solved by the craftsmen in different ways, depending on their qualifications and contractual conditions with the owner.
Some explanations and recommendations can be found in the article in our article Repair of Samsung, LG LED-backlights.
Of the most common malfunctions of Samsung CRT TVs, there are several associated with the low reliability of CRTs and their deflecting systems (OS).
The consequence of shorting the filament with the cathode of the kinescope (usually green) is eliminated by isolating the filament from the mass and organizing its separate power supply (2-3 turns per TDKS core). In this case, do not forget to use the standard filament current calibration resistor.
In kinescopes with a flat screen, diagonals of 20 inches or more, a short circuit between the accelerating electrode and the modulator (G2 and G1) often occurs, which is accompanied by the absence of an image.
Fortunately, such short-circuits, in most cases, can be easily eliminated by the usual old-fashioned methods popular among repairmen.
It is more difficult with the closure in the lowercase deflecting coils of the CRT. In this case, the line transistor short-circuits, usually immediately upon switching on. In some cases, you can see smoke from under the throat of the OS, feel the characteristic smell, the transistor (HOT) overheats at this time.
A lot of trouble in many models of Samsung CRT-TVs of different diagonals is delivered by the elements of the IOC capacitive divider of the horizontal sync pulse formation circuit. In such cases, the limiting resistor often burns out to charcoal, sometimes damaging the board section along with the conductive tracks.
In cases with “floating” defects, when it is not possible to detect poor contact in the soldering of the element leads, it is necessary to remember the specificity of the metallization of the holes in the power circuits of the horizontal scan, which is characteristic of Samsung CRT TVs.
The contact of the metal sleeve with the copper pad of the board is often painted over, sometimes it is faster to detect sparking in this place than to see an annular crack with a magnifying glass.
Most often, such a breakdown of contact occurs at the place of soldering of the contact pad with metallization of the collector connection of the line transistor.
Typical malfunctions of some common models made on standard chassis can be considered separately.
Pages will be added as the material is prepared.
Typical defects and repair of Samsung chassis KS1A - From the practice of repairing Samsung KS1A TVs.
Typical defects and repair of Samsung chassis KS2A - From the practice of repairing Samsung KS2A TVs
According to the functional composition of CRT (with a kinescope) and LCD (LCD) TVs, separate sections have been created on the site, where modules and elements for well-known and popular models for repair are indicated in the tables:
Composition of Samsung CRT TVs - Functional composition of Samsung CRT TVs.
Composition of Samsung LCD TVs - Functional composition of Samsung LCD TVs.
Some useful recommendations for owners who decide to buy a new TV due to the unrepairability of the old one can be found on the page: how to choose a TV when buying.
Comments and suggestions are welcome!
It is no secret that a breakdown of a television receiver can ruin the mood of any owner. The question arises, where to look for a good master, do you need to take the device to a service center? You need to spend your time on this, and what is important - money. But, before calling the master, if you have basic knowledge of electrical engineering and know how to hold a screwdriver and a soldering iron in your hands, then repairing the TV with your own hands in some cases is still possible.
Modern LCD TVs have become more compact and easier to repair. Of course, there are breakdowns that are difficult to detect without special diagnostic equipment. But most often there are malfunctions that can be detected even visually, for example, swollen capacitors... With such a breakdown, it is enough to evaporate them and replace them with new ones with the same parameters.
All TV sets are the same in their structure and consist of a power supply unit (PSU), a motherboard and an LCD backlight module (lamps are used) or LED (LEDs are used). It is not worth repairing the motherboard on your own, but the power supply unit and screen backlight lamps are quite possible.
As already mentioned, the design and principle of operation of LED and LCD TVs, regardless of the manufacturer, are the same. Of course, there are some differences, but they do not play a significant role in the diagnosis of faults. Often, in the event of a problem with the power supply, the LCD TV does not turn on at all, while there is no indication, or it turns on for a while and turns off spontaneously. Using an example, the repair of a DAEWOO LCD power supply unit (can be applied to plasma) is considered, which is not much different from repairing an LG TV, as well as Toshiba, Sonya, Rubin, Horizon and similar models.
- First of all, before you repair the TV, you need to remove the back panel of the device with a screwdriver by unscrewing the screws. On some models, the rear wall may be latches installedwhich must be handled with care so as not to break them.
- After removing the cover, you will see the power supply unit, consisting of several modules on the left, and the motherboard on the right.
- On the power supply board you can see 3 transformers: the bottom one is the mains rectifier choke, the top one on the left (large) feeds the inverter, and on the right is the standby power supply transformer. You need to start checking with it, since it turns on the standby mode of the TV receiver.
- Duty transformer when the device is connected to the network, it should give out a voltage of 5 V. In order to correctly find the wire on which you need to measure the voltage, you can use the diagram, or you can see the markings on the case. In this case, opposite the required contact is written - 5 V.
Measurement is taken first open circuitby connecting one probe to the found contact, and the other to the cathode of the diode on the radiator. In this case, there is no break. 
As you can see from the review presented above, repairing TV power supplies with your own hands is not such an overwhelming task. Following this description, you can also repair plasma TVs.
Do-it-yourself TV repair with a kinescope, for example, such as: Rubin, Horizon, Sharp 2002sc, LG TVs, as well as repair of the Vityaz TV, begins with checking the power supply unit for operability (this is done if the unit does not turn on). It is checked using incandescent bulbs for 220 V and a power of 60-100 W. But before that, be sure to disconnect the load, namely the horizontal output stage (SR) - connect the lamp instead. The CP voltage ranges from 110 to 150 V, depending on the size of the tube. Must be found in the secondary circuit SR filter capacitor (its values can be from 47 to 220 microfarads and 160 - 200 V), which stands behind the SR power rectifier.
To simulate the load, you need to connect a lamp in parallel to it. To remove the load, for example, in the popular Sharp 2002sc model, it is necessary to find and unsolder the inductor (located after the capacitor), the fuse and the limiting resistance through which the CP stage receives power.
Now you need to connect the power supply to the power supply unit, and measure the voltage under load. The voltage should be between 110 and 130 V if the CRT has a diagonal of 21 to 25 inches (as in the 2002sc model). With a diagonal of 25-29 inches - 130-150 V, respectively. If the values are too high, then it will be necessary to check the feedback circuit and the power supply circuit (primary).
It should be noted that electrolytes dry out during prolonged operation and lose capacity, which, in turn, affects the stability of the module and contributes to an increase in voltage.
When the voltage is too low it is necessary to test the secondary circuits to exclude leaks and short circuits. After that, the diodes for the protection of the power supply of the SR and the diodes for the power supply of the vertical scan are checked. If you are convinced that the power supply unit is working properly, then you need to disconnect the lamp and solder all the parts back. This check can also come in handy when doing DIY Philips TV repairs.
Another common breakdown of the TV that can be eliminated is the burnout of the backlight lamp. In this case, the TV receiver, after switching on, flashes the indicator several times and does not turn on... This means that after self-diagnosis, the device notices a malfunction, after which the protection is triggered. That is why there is no image on the screen.
For example, a Sharp LSD TV receiver with this malfunction was taken, although in this way it is possible to repair Samsung TVs, Sony Trinitron, Rubin, Horizon, etc.
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To fix the TV, you need to remove the back panel from the TV. This requires a screwdriver or screwdriver.
Next, you need to be careful disconnect loops from the matrix. 
Thus, you can repair the Philips and LG TV with your own hands, and other LCD panels, as well as devices with LED backlight (LED). Owners of the latter type of devices should read the article on repairing LED backlighting, where the whole process is described in detail using the example of an LG TV.
Among the typical and simple reasons that the TV set does not turn on, there may be a remote control or a lack of signal from the antenna cable.
If the TV does not turn on with the remote control, first, you need to make sure the batteries are valid. If they are shrunken, replace them. Often the TV set cannot turn on due to contamination of contacts under the buttons. To do this, you can disassemble it yourself, and clean the contacts with a soft cloth from accumulated dirt. If your remote control has been dropped, it is possible damage to the quartz emitter... In this case, it must be replaced. Well, if you filled the remote control with water or some other liquid, and it did not work after disassembling and drying, then it will have to be replaced with a new one.
You can learn more about fixing the remote control in the following video or article.
When repairing TVs LG, Sharp with LCD, Rubin, Horizon with the same screens, a situation often arises when it does not turn on when the device is in good working order. It turns out that the reason may be no TV signal in the antenna cable. This happens due to the operation of the noise suppression protection (in Rubin TVs, they began to install it not so long ago), and the unit goes into standby mode. Therefore, if you find your TV set in an inoperative state, you should not panic, but you need to check the presence of a signal from the transmitting station.
In conclusion, we can say that when you decide to repair a TV set yourself, you should soberly assess your abilities and knowledge in this matter. If you do not feel confident, then it is better to entrust this matter to a telemaster, especially since nobody canceled 220 V, and ignorance of basic safety rules can entail unpleasant consequences.
As much as we would not like it, but household appliances, especially electronics, tend to fail. In this article, we will tell you in detail what to do in case of vertical stripes on the Samsung LE40A454C1 TV.
It should be said that this type of malfunction is quite popular for this model. It is associated with improper operation of decoders or controllers of the liquid crystal matrix. They are microcircuits that convert the signal responsible for the color and activation of pixels. The so-called drivers are usually executed on flexible stubs along the entire matrix, dividing it into several segments.
In this case, the number of loops is eight, and they are all located at the top.Each has a driver through which the signal is transmitted to the matrix.
In order to gain the necessary access, you will need to disassemble the panel, for which it is placed with the screen down, on a previously prepared substrate so as not to damage the surface. Then all the cover screws are unscrewed.
Meanwhile, each model of Samsung LE40A454C1 TVs has an information plate with primary information.
There are also several interface elements through which you can connect other devices or display an image on them.
The cover can be removed easily. After that, access to the signal processing unit, the battery, the backlight board, protected by a dark overlay, appears. To carry out the repair, it will be necessary to provide an approach to the upper part of the matrix, where the loops pass, therefore, the frame is also dismantled. This can be done simply by unscrewing the corresponding bolts.
If there is a suspicion that the power board is working, it is also recommended to remove it by unscrewing the indicated screws and disconnecting the ribbon cable.
We do the same with the signal processing board.
The backlight board is checked only to ensure that all connectors are securely fixed.
You can see that the speakers are located at the bottom of the case, and to prevent unnecessary vibration, they are fixed on rubber suspensions.
Moving on to removing the metal cover that covers the power supply.
Having done this, access to the intermediate board with loops is freed up, which are neatly dismantled. It is recommended to do a visual inspection for solder delamination and cracks.
Now all the boards are installed in place, if no defects are noticed, you can turn over and turn on the TV. Non-working drivers are determined by the nature of the distribution of colors and stripes.
A detailed photo allows you to see one of these drivers, which is responsible for the color rendition of pixels. The problem appears due to marriage, overheating or mechanical contacts, as a result of which the specified element peels off.
With minimal force on the train, the image usually returns to normal. If there were no falls and unskilled intervention, then the problem is often of a factory nature. In such situations, the defect is also observed on neighboring loops.
The easiest way to restore contact is to fix it with double-sided tape to the metal frame around the entire perimeter. This, above all, will provide additional protection against mechanical stress.
It will not be superfluous to additionally apply a seal, which is used for packaging electronic components.
You will get a sealing cushion, which allows you to efficiently press all the matrix cables to the connecting tracks.
If, as a result of assembly, the height of the seal is not enough, then you can apply it in two layers, or choose another one.
The likelihood of achieving the desired effect is high. Otherwise, you will have to look for a special conductive glue, in fact, with the help of which the factory connection of the contacts is made.
Recently, they began to bring many TVs with repaired LED backlighting, they die after 9 months - 1 year of use, after repair.
Usually I have a stream of 1-2 TVs with this problem per week, all spare parts are in stock, I do repairs during the day. But this week something flooded, 4 TVs, two of which after other masters. Here are the actual Masterpieces:
p.s: At the bottom of the post I will write what needs to be done to work longer.
What burned out is the norm for samsungs, but how they did it, of course, pc
It's good that the master restored the reflector in the place of burnout, but why the heck was to paint over the diffusers of the LEDs in white and cover them with paper?
Since I'm buying broken TV, I have where to get donor organs;), I changed all the suspicious and non-working LEDs, and then put good diffusers on them. Here is the result:
After that, I trimmed the reflector a little more so that it would not clutter up on the diffusers, I collected it and voila.
Another TV, this time LG, there is generally a trick - how not to do it!
Just a jumper instead of an LED. I see no reason to show the finished result, but in fact I just say, for the masters, it is not necessary.
Even if the current stabilization will bypass this jamb, and underestimate the current, and the rest of the LEDs will not burn out, but a badge, a dark spot on the screen does not bother anyone ??
Now is the time fucking stories tell how to do it:
After repair, replacing all non-working and suspicious (those that blink before turning on) LEDs, you need to programmatically or hardware lower the maximum brightness by 20 percent, there will be no difference by eye, but the service life will last several times. From the factory, an overestimated current goes to the LEDs, because of this, they actually burn out.
On LG we go to the service menu, and there we adjust the percentage of maximum brightness (it’s a little gimmicky to do this without a service remote control, but then you are a master, so that you either have it, or find a bypass in the form of two LEDs and a sound file ;-) )
On Samsungs, we are looking for a resistor next to the backlight loop, the nominal value is usually 3.17 3.6 Ohm, and we add in series with it, a resistor by 1 Ohm, thereby increasing the total resistance in the circuit, and the voltage drop across these resistors, which actually regulates the brightness of the backlight: The more resistance / current, the greater the voltage drop, the lower the brightness of the backlight (stabilization occurs relative to these parameters)
Well, actually everything, good craftsmen for you, and for the masters of successful repairs
Today we will be with you repair lcd tv Samsung, or rather, we will eliminate the malfunction that occurred in LED backlight of this unit.
So, I entered the repair led TV set Samsung, model UE42F5500AK, with LED backlight.
According to the client, the TV screen first darkened at the top, and then went out altogether. At the same time, all other functions worked properly, i.e. there was sound, channels were switched, etc. Also, when you shine a flashlight on the matrix, you can see the image.
With these symptoms, two options can be assumed - either the power supply has failed (power is not supplied to LED backlight), or the backlight itself is out of order (the LEDs have burned out, the power supply along the paths in the backlight strips has been disrupted).
In the first case, you need to check the power circuit from the secondary winding of the transformer to the contactor, which goes to the backlight itself, as well as the led driver, consisting of the SLC5012M PWM controller and two keys, which are assembled on N-channel field-effect transistors D3N40. Also, in this case, you need to check the power to the PWM controller itself.
In the second case, you will need to remove the matrix to get to LED backlight, and then, using a multimeter, make the necessary measurements in order to identify the cause of the malfunction: check the tracks in the backlight strips and, if they are working properly, check the LEDs of this backlight.
It turned out that the power supply was in working order, even power was supplied to the TV backlight (when the device was turned on).
Based on this, it was concluded that the backlight of the TV matrix was faulty. To get to it, it was necessary to remove the matrix and diffusers from the body, which was done.
After that, I began to check the LEDs, of which there were 98 pieces (7 strips of 14 LEDs each).
The strips had contacts to which it was possible to connect the probes of the device to test the LEDs. When connecting the multimeter probes to the contacts on the bar, observe the polarity, since these LEDs have "plus" and "minus". If the connection is correct and the LED is working properly, the LED will light up. If the connection is correct and the LED is off, then this LED is faulty. Also, if the LED shows a short circuit, then in this case the diode is faulty.
In order not to check all the LEDs, you can alternately supply a constant voltage of 25 ... 35V to the strips. In this case, a bar with good LEDs will work, i.e.all LEDs on this bar will light up. The bar on which the LEDs will not light up should be subjected to a more thorough check by measuring each LED separately.
In general, after doing the above verification procedures LED backlight, two faulty LEDs were found, located on the first and fifth strips.
So, the reason for the inoperability of the TV was identified, now it remains to produce backlight replacement, namely, two failed LEDs.
It is not so easy to do this, since such LEDs are not commercially available (at least in our country). In this regard, it was decided to install LEDs from the donor bar. Donor trims can be found in workshops or service centers if an intelligent craftsman comes across. In my case, an intelligent master was found.
There are two ways to replace the LED - to remove the faulty and serviceable LEDs and install a serviceable one instead of the faulty one. To evaporate such an LED, you need to remove the reflector from it and use a soldering hairdryer to heat the bar from below, in the place of the LED to be soldered, until the LED freely "lags" from its place. This must be done very carefully so that the LED does not melt, as they are very delicate. And to solder the diode, you need to use a soldering iron with a thin tip (do not forget about the polarity of the LEDs).
I used another, easier way, in which the melting of the LED is almost impossible.
In general, I took a bar with a faulty LED and cut this LED along with parts of the bar on both sides with a hacksaw.
Then he stripped the paint off the tracks into parts with the LED and at the cut-off points of the strip, and then simply soldered the tracks.
I use this method all the time, because the probability of the LED melting when soldering is very high and the loss of a couple of LEDs in case of an unsuccessful "operation" is not very acceptable for me.
Having done everything that is described above, with both strips on which there were faulty LEDs, I installed them in the TV case and made a test switch on the device without a matrix.
Well that's it, backlight replacement, or rather LEDs in the backlight, was successful. Now it remains to install the matrix in the TV case, assemble the device completely and try to turn it on.
After such a repair, I always give advice to the client not to use the TV set with the backlight brightness set to the maximum value (not the image brightness, but the backlight brightness, there is such an adjustment in the menu), as this can lead to the same breakdown after a while.
But, in order not to limit the clients in any way, recently I began to simply modify the power supply unit, reducing the current that goes to the backlight. How to make such a revision, the speech will go to next article .
Hello! Do you have the original image of the TV set before the repair?
In the original version, there was no backlight at all, there was just a dark screen.
Hello Victor, can you tell me how many volts and watts are in the LED TV backlighting samsung ue40f6130ak, thank you in advance.
Hi Aleksey! Even the same models have different LEDs. Typically 3.3V 1W.
Good afternoon! Victor, we have the same thing and the TV is the same ... I was told that it is better to completely change the backlight, otherwise the opposite may happen again ... but the price does not suit ... how long do you think will last if you change only those diodes that have burned out ?!
As much as with the new one. The new backlight may also burn out after a week. If you put similar diodes, it will work like new.
Please tell me the model of the LEDs.
I don't know the model, but the parameters are 3.3V 1W.
Could you tell us about the dimensions of the LEDs?
tell me the cost of this procedure if you completely change the backlight?
and how is this considered a breakdown due to my fault or is it a factory defect or a defect?
The cost of replacing the ENTIRE backlight is quite costly.If the guarantee for the TV has not yet come out, then this is considered the fault of the manufacturer.
Greetings, I can't understand what's wrong with the TV, the screen has become faded, dark — not bright, like after the store, there are several light spots left. Shows all channels in this mode. Tell me the breakdown ... ... what's wrong with it? What to do?
Little information ... maybe the LEDs in the backlight have burned out.
If the LEDs burn out, then you said that if one LED burns out, then all the backlight lines will not work. And also, if possible, tell me the marking of the LED lines for Samsung UE40H550AK TV and how many are there
Hey! If at least one diode is broken, then either the entire screen or part of it, depending on the model, will not glow. And if the diodes are short, then the serviceable ones will glow. Your TV model has D4GE-400DCA-R2 (R1) lines and there are 45 of them.
Hi, it turns out they are in short - many of them.
but this could be? interesting case,
45 LEDs, and 5 strips of 9 LEDs.
can send you a video if you don’t believe
hello, only one is on, and the other line shows resistance and nothing is on, I have 24 pieces, two lines, and if you put a separate power supply for other LEDs and replace these with others and there will be a separate power supply will not affect the operation of the TV
Victor, greetings. My model is UE32F5020AK, no backlight. 3 diodes burned out, while there is nothing to replace, but there are doubts about the power supply unit. What to measure and what parameters should be? I have 210 volts on the C9102. Does this definitely mean that the power supply unit is working properly? If not, what else to check? I tried to solder 3 round diodes instead of broken diodes, which also ignited from 3 volts. For some reason, this option caught fire on its own (although the Samsungs sometimes turn on when the plug is inserted), but after a couple of seconds it went out when the donor diode began to smoke. What do you advise?
Probably, the donor diodes are low-power, so they flew out right away. Just replace the burnt out LEDs and reduce the backlight current.
Good afternoon. Can you please tell me how many LED tracks are there in the Samsung UE40H5020AK TV backlight? Recently I took my TV to the service (several LEDs in the backlight burned out) and they said that it had almost 14 lines of LEDs (horizontal and vertical)! I doubt it, so I decided to ask you. Thank you in advance for your response!
It happens in different ways. Let them show you if in doubt.
Hello! please tell me what could be the reason for the malfunction Samsung smart TV - From the right edge the image began to float, the closer to the center the better ... and on the right it is almost black and white and blurry ...
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It is no secret that a breakdown of a television receiver can ruin the mood of any owner. The question arises, where to look for a good master, do you need to take the device to a service center? You need to spend your time on this, and what is important - money. But, before calling the master, if you have basic knowledge of electrical engineering and know how to hold a screwdriver and a soldering iron in your hands, then repairing the TV with your own hands in some cases is still possible.
Modern LCD TVs have become more compact and easier to repair. Of course, there are breakdowns that are difficult to detect without special diagnostic equipment. But most often there are malfunctions that can be detected even visually, for example, swollen capacitors... With such a breakdown, it is enough to evaporate them and replace them with new ones with the same parameters.
All TV sets are the same in their structure and consist of a power supply unit (PSU), a motherboard and an LCD backlight module (lamps are used) or LED (LEDs are used). It is not worth repairing the motherboard on your own, but the power supply unit and screen backlight lamps are quite possible.
As already mentioned, the design and principle of operation of LED and LCD TVs, regardless of the manufacturer, are the same. Of course, there are some differences, but they do not play a significant role in the diagnosis of faults. Often, in the event of a problem with the power supply, the LCD TV does not turn on at all, while there is no indication, or it turns on for a while and turns off spontaneously. Using an example, the repair of a DAEWOO LCD power supply unit (can be applied to plasma) is considered, which is not much different from repairing an LG TV, as well as Toshiba, Sonya, Rubin, Horizon and similar models.
- First of all, before you repair the TV, you need to remove the back panel of the device with a screwdriver by unscrewing the screws. On some models, the rear wall may be latches installedwhich must be handled with care so as not to break them.
- After removing the cover, you will see the power supply unit, consisting of several modules on the left, and the motherboard on the right.
- On the power supply board you can see 3 transformers: the bottom one is the mains rectifier choke, the top one on the left (large) feeds the inverter, and on the right is the standby power supply transformer. You need to start checking with it, since it turns on the standby mode of the TV receiver.
- Duty transformer when the device is connected to the network, it should give out a voltage of 5 V. In order to correctly find the wire on which you need to measure the voltage, you can use the diagram, or you can see the markings on the case. In this case, opposite the required contact is written - 5 V.
Measurement is taken first open circuitby connecting one probe to the found contact, and the other to the cathode of the diode on the radiator. In this case, there is no break.
As you can see from the review presented above, repairing TV power supplies with your own hands is not such an overwhelming task. Following this description, you can also repair plasma TVs.
Do-it-yourself TV repair with a kinescope, for example, such as: Rubin, Horizon, Sharp 2002sc, LG TVs, as well as repair of the Vityaz TV, begins with checking the power supply unit for operability (this is done if the unit does not turn on). It is checked using incandescent bulbs for 220 V and a power of 60-100 W. But before that, be sure to disconnect the load, namely the horizontal output stage (SR) - connect the lamp instead. The CP voltage ranges from 110 to 150 V, depending on the size of the tube. Must be found in the secondary circuit SR filter capacitor (its values can be from 47 to 220 microfarads and 160 - 200 V), which stands behind the SR power rectifier.
To simulate the load, you need to connect a lamp in parallel to it. To remove the load, for example, in the popular Sharp 2002sc model, it is necessary to find and unsolder the inductor (located after the capacitor), the fuse and the limiting resistance through which the CP stage receives power.
Now you need to connect the power supply to the power supply unit, and measure the voltage under load. The voltage should be between 110 and 130 V if the CRT has a diagonal of 21 to 25 inches (as in the 2002sc model). With a diagonal of 25-29 inches - 130-150 V, respectively. If the values are too high, then it will be necessary to check the feedback circuit and the power supply circuit (primary).
It should be noted that electrolytes dry out during prolonged operation and lose capacity, which, in turn, affects the stability of the module and contributes to an increase in voltage.
When the voltage is too low it is necessary to test the secondary circuits to exclude leaks and short circuits. After that, the diodes for the protection of the power supply of the SR and the diodes for the power supply of the vertical scan are checked. If you are convinced that the power supply unit is working properly, then you need to disconnect the lamp and solder all the parts back. This check can also come in handy when doing DIY Philips TV repairs.
Another common breakdown of the TV that can be eliminated is the burnout of the backlight lamp. In this case, the TV receiver, after switching on, flashes the indicator several times and does not turn on... This means that after self-diagnosis, the device notices a malfunction, after which the protection is triggered. That is why there is no image on the screen.
For example, a Sharp LSD TV receiver with this malfunction was taken, although in this way it is possible to repair Samsung TVs, Sony Trinitron, Rubin, Horizon, etc.
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To fix the TV, you need to remove the back panel from the TV. This requires a screwdriver or screwdriver.
Next, you need to be careful disconnect loops from the matrix.
Thus, you can repair the Philips and LG TV with your own hands, and other LCD panels, as well as devices with LED backlight (LED). Owners of the latter type of devices should read the article on repairing LED backlighting, where the whole process is described in detail using the example of an LG TV.
Among the typical and simple reasons that the TV set does not turn on, there may be a remote control or a lack of signal from the antenna cable.
If the TV does not turn on with the remote control, first, you need to make sure the batteries are valid. If they are shrunken, replace them. Often the TV set cannot turn on due to contamination of contacts under the buttons. To do this, you can disassemble it yourself, and clean the contacts with a soft cloth from accumulated dirt. If your remote control has been dropped, it is possible damage to the quartz emitter... In this case, it must be replaced. Well, if you filled the remote control with water or some other liquid, and it did not work after disassembling and drying, then it will have to be replaced with a new one.
You can learn more about fixing the remote control in the following video or article.
When repairing TVs LG, Sharp with LCD, Rubin, Horizon with the same screens, a situation often arises when it does not turn on when the device is in good working order. It turns out that the reason may be no TV signal in the antenna cable. This happens due to the operation of the noise suppression protection (in Rubin TVs, they began to install it not so long ago), and the unit goes into standby mode.Therefore, if you find your TV set in an inoperative state, you should not panic, but you need to check the presence of a signal from the transmitting station.
In conclusion, we can say that when you decide to repair a TV set yourself, you should soberly assess your abilities and knowledge in this matter. If you do not feel confident, then it is better to entrust this matter to a telemaster, especially since nobody canceled 220 V, and ignorance of basic safety rules can entail unpleasant consequences.
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