Do-it-yourself dns e24d20 TV repair does not turn on

Material is added to the pages as data accumulates from the available technical documentation, personal author's experience and from the masters of repair forums. More details.

Panel: CX236LEDM / M236H1-P08

LED driver (backlight): integrated into PSU

Power Supply (PSU): MP113TH-50

E24D20 Specifications

- DNS E24D20 does not turn on and does not show any signs of operability. Does not blink indicators and does not respond to any control buttons.

In such cases, the MP113-TH50 power supply usually fails. It is necessary to measure the secondary output supply voltages, and if they are absent, check the serviceability of the power switches of the converters and rectifier diodes for a short circuit.
In case of breakdowns in the secondary circuits, the converter can operate in short-circuit mode, and in case of short-circuit in the elements of the primary circuit, the mains fuse is usually cut off.
Mos-Fet keys used in switching power supplies usually fail due to a malfunction of other elements that can disable it in the key mode, or provoke an excess of the maximum current or voltage values. These can be supply, damper circuits, or elements of OOS (negative feedback) stabilization. The reason for the breakdown of the power switch can also be the PWM OB2273 (PWM SOT23-6). It is checked only by replacing it with a known good one.

- There is no picture, but there is sound and reaction to the remote control. Or, for a second, the image may appear immediately after switching on.

In such cases, a malfunction of the LED panel backlighting elements is most likely. The reason may be both in the power supply of the LEDs, in their serviceability (breakdown or breakage), as well as in the violation of the contact connections of the LED strips.
When diagnosing, it must be borne in mind that it is impossible to check for an open in the circuit of the LED lines without disassembling the panels using a tester or multimeter. To open all PN junctions connected in series, a voltage of the order of several tens of volts is required, and ideally a current source. By opening the panel, you can check each LED separately. Typically, Chinese multimeters will lightly light one 3-volt LED if you connect the probes to it in the forward direction. For dual 6-volt LEDs, the PN junction of its emergency zener diode can serve as an indicator of the LED health. In the event of a malfunction of the LED, its zener diode will either be cut off, or broken through in the K / Z.

- The indicator blinks or is on constantly, the TV does not turn on, does not respond to the remote control.

Repair or diagnostics of the T.MSD309.B63B motherboard should begin with checking the stabilizers and power converters necessary to power the microcircuits and matrix. If necessary, you should update or replace the software (software). Complex repair of MB (SSB) is possible only in a service center with the necessary equipment. Checking or replacing 25Q32BSIG elements requires the necessary training and professional skills to repair modules at the component level. Problems associated with the use of BGA soldering technologies can sometimes be diagnosed by the warm-up method.

If the TV operates normally from external devices but does not tune to TV channels, the Tuner may be faulty. In such cases, first of all, you should make sure that there are supply voltages at its corresponding terminals. It is also necessary to make sure that it is possible to exchange data between the tuner and the processor via the I2C bus.Sometimes the reason for the inoperability of the tuner may be a software failure.

Remember! Attempts to self-repair the DNS E24D20 TV, in the absence of the necessary qualifications and experience, are categorically not recommended and are fraught with negative consequences, up to the complete non-repairability of the device!

The appearance of the MainBoard T.MSD309.B63B is shown in the figure below:

The main features of the DNS E24D20 are:

Installed matrix (LED panel) CX236LEDM / M236H1-P08.
Matrix control uses Timing Controller (T-CON) M236H1-P08.
To power the backlight LEDs, a converter combined with a power supply is used, controlled by a BIT3251 PWM controller.
The formation of the necessary supply voltages for all nodes of the DNS E24D20 TV is carried out by the MP113TH-50 power module, or its analogs using LD7536 microcircuits (PWM SOT23-6).
MainBoard - the main board (motherboard) is a T.MSD309.B63B module, using 25Q32BSIG chips and others.

Information about the composition of televisions on this site is accumulated from the records of repairmen and forum participants.
Be careful! Typos and errors possible!

The problem is known - after a while, DNS brand TVs stop turning on (leaving the stand-by). Usually, before this, first there are refusals to exit the standby mode from the first time, then it exits only after repeatedly pressing the power button, then it stops turning on completely.

The question is, is it really possible that the problem has not been defeated?

an immodest question - how many of them do you have?

why an immodest, quite logical question))

there were two, bought at a low price with quite decent characteristics.
I changed one after the second repair under warranty, the second did not have time - it was repaired once in a service center, then the warranty ended. now he shows Malevich very clearly.
light googling showed that the problem is global, while the source of the problem is silence.

in the coupon after the service repair they write “software update”, but I strongly doubt that this is true.
in fact, maybe just some containers are dying.
Well, I do not believe that local craftsmen have not heard about this.

ADDED February 22 2015

come on first - can you solder?
And what about the SMD?
A hairdryer?
Can you find an SPI programmer?
And where will you get the flash chip?
will they dump you? good people .

Now it’s logical - if you’ve never done it before - and you don’t need to.

For the time spent on repairs, earn money elsewhere
there will be more than the master will receive for this, and will also remain for ice cream.

let others earn money,
and get down to business yourself, you look and you will be lucky in something.

well, why immediately swear like that))
I can solder, my hands seem to be straight. at least smd 0805, soic soldering, have not tried less. no soldering station, but there is an adjustable soldering iron, works well.
there is no soldering hair dryer, there is an industrial one with nozzles, it solders the smd normally.
There is no spi-programmer, only avr, well, if it's a cheap model, I'll take it on ebee, there's a flash in the same place.

no dump

telly M32AM8

if so stubborn. [DELETE]

Maverik2210, there is no customer support!

yes, in general, I needed to understand what the problem was. it turned out that the firmware was almost unambiguously flashed.
they even gave a tip about what programmer is needed, etc. the rest is a matter of technology.

yes, and to make your personal redneck position more clear to you, imagine - you come to the doctor and say, “what’s the matter with me, will I live?” and the doc says to you - "that xs, give five hundred greens, and drink these pills, and what about you I won't tell you, you don't need to know that." and now you drink pills for five hundred dollars and recover, not even suspecting that you had ordinary bronchitis and you could be cured simply by brewing thyme herb on your own.

And so it will definitely be with you, believe me - life is such a thing - everything comes back in it.

Kvas, moron, are you tired of feeding customers? Do you like to pose as a great specialist? Too much work? Well duck it will pass soon.

Your position is clearer to us - the position of the BABYRUSHKA. You locked yourself on the forum, without even bothering to read the rules, you did not create a topic that could be useful to the forum, and therefore to many users. You just held out your hand, hoping for a handout, and you got it (there was a half-wit).

Here we help EVERYONE who is able to follow simple rules, meaningfully ask a question, and meaningfully answer questions from participants. Unfortunately, these are becoming less and less, but more and more all sorts of beggars emerge.

Kvas, of course, you are free to dispose of your money, you can distribute them on the porch as much as you want. But HERE you donate not only your money, but also the money of those who did not ask you for it.

Now you have snatched other people's money, and you are triumphant. Perhaps some master in your area sat over a similar problem at night and eventually defeated it on his own. And now he got a spit in the face from you, and another jerk.
So everything will come back. Here you unjustly snatched, in another place you will lose. I hope more.

All about Maverik2210

Peeking
Registered: 12.02.2008 [With us 2568 days]

what did you repair last time? helped here?

Unsubscribe about the result on the topic, only the truth

... It is interesting - the master will “rip off” you after the “qualified” intervention.

Yuritsh, right, if you want to be helped - take at least a step towards (arrange a topic, etc.)

ADDED Feb 23 2015

Yuritsh, I am now in the same situation as the TS, although not a client like

I opened a neighboring topic - the ASTshniki did not even move. Sorry for a piece of bread? not even his own, someone else's.

Yuritsh, can you help, or how? or how is everyone?

https://my.housecope.com/wp-content/uploads/ext/2254/section31/post1942375.html#1942375

Maverik2210, and to you an answer for the hint - will you throw off the dump from your DNSa to the forum? OK? I am waiting.

my.housecope.com/wp-content/uploads/ext/42

Home electronics repair E24D20 DNS TV flashes LED and reboots - SPI Flash flashing

The DNS E24D20 TV (chassis: T.EME380.61, matrix: CX240LEDM) is being repaired, the owner complains: “it took a long time to turn on”. When turned on, the backlight turns on, then the LED starts blinking in green and red for a long time, after which the screen goes out for a moment and everything repeats from the beginning.

An autopsy did not reveal swollen capacitors, the supply voltage from the power supply is normal, there are no ripples.

Symptoms indicate that the TV is loading the firmware, but something goes wrong and a reset occurs. But, as it turned out, this does not always happen. If you have patience and wait, then after a random number of such resets, the TV will still turn on and work quite normally. This behavior was somewhat puzzling: after all, if the firmware “flew off” or the memory chip itself, which stores the firmware, is faulty, then how does the TV manage to work?

Entering the service menu for this TV is MENU, 1147. Resetting the settings does nothing, flashing via USB is impossible (although there is a USB Update item in the menu, but it does something else - it probably reinitializes USB).

There is nothing to do, the firmware will have to be changed through the programmer. First, we read the native firmware from the SPI Flash 25Q64 microcircuit. This is necessary just in case, because there may not be any firmware for DNS E24D20 on the Internet or they may be incorrect. We read 8 megabytes with the programmer.

A search on the Internet leads to the fact that there are no open source firmware for the DNS E24D20 T.EME380.61 TV. They are present only on sites where downloading them is extremely difficult, up to extortion of money, viewing ads, after which, by the way, it is still impossible to download. Comes to the rescue. DNS site. On it, the firmware for this TV is completely open. Downloading, comparing with the native one - for the most part the same, but there are several different pieces. This confirms the assumption that the native firmware still flew off.

We clean the microcircuit, but we receive an error message: writing is prohibited. We programmatically remove the write protection, program the microcircuit and install it back into the TV. It turns on successfully and quickly, prompting you to make the initial settings in the menu. We search for channels - the TV works great, turns on, again, quickly.

The repair was carried out practically without a soldering iron. True, the 25Q64 microcircuit still had to be evaporated (the photo shows the place where the microcircuit was installed), because did not dare to supply power to it directly on the board. When programming, you should set the voltage that is indicated in the datasheet for the SPI Flash chip, in this case - 3.3 volts.After programming, it is imperative to do verification to make sure that the microcircuit is fully operational. For firmware, you can use the most available CH341A programmers and a flashed USBAsp.

The TV itself made a double impression. On the one hand, it works pretty well for its class, all connections inside are made on connectors, it is convenient to repair. On the other hand, the parts of its case and even the PCB itself are so flimsy that they bend when touched. Not otherwise, this model is the first step towards a flexible TV.

The TV is in standby mode (red LED is on). It does not respond to pressing the "On" button on the TV case, or any button on the remote control. What to do?

It is forbidden to write answers that do not bring any benefit to the questioner from the series: “bring it to the service”, “contact the ASC”, “unprofitable”, etc. Answers like these will be considered a rating cheat, the answers will be deleted, and the account will be blocked.

If you undertake to help people, answer fully. Explain why, if you recommend, for example, reflashing your phone, then write how to do it. If you write that repairs are unprofitable, explain why.

Check the capacities in the power supply and the signal flow to the processor.

It is impossible to imagine a modern apartment or house without video and audio equipment. This equipment is used every day and therefore breaks down more often than others. There are several ways to repair TVs: send the technician to a service center, call a qualified technician at home, or make repairs with your own hands.

Before you start repairing a TV, you first need to make sure what the problem is. This will also help if you do the repair yourself, and then when the master comes, you will be able to explain the situation to him.

There are several types of malfunctions that can most often be found when a TV breaks down.

1. The technique does not turn off. In independence, a CRT TV or a modern LCD model has broken down, this malfunction is associated with a blown fuse. Only different models have distinctive details from each other. You should also pay attention to the diode bridge - perhaps it was he who burned out.
2. In both domestic and imported models, the potential can often go astray, for the function of which the posistor is responsible.
3. If the plasma TV monitor is broken, then the problem, most often, is interference or drops, light or dark stripes may appear, color changes while watching a program or movie.
4. The problem may be a broken cord or a faulty outlet.

If we take into account all the troubles listed above, it is worth saying that the most difficult breakdown is considered to be a screen malfunction. For example, light reflections appear on your monitor after the liquid hits the matrix or the TV is hit, then it is better to carry it to the teleservice. Here it will certainly be repaired, and if the warranty period has not expired, then it will be free of charge or at a reduced price.

See also - How to choose a TV for your home in 2018?

You can try to fix some malfunctions of TVs yourself. And it doesn't matter here - these are LCD models, LCD or LED, it is not necessary to call the wizard if you are confident in your abilities. But caution never hurts, because such TV models are not cheap, and without having any repair experience or knowledge in this area, you can only harm and aggravate the breakdown.

Before you start repairing LED or LCD TVs, you must carefully read the instructions, and also study the principle of operation of your model. Anyone, even one far from this field, will understand that the repair of TVs such as LCD or LED will differ from CRT models. In the latter case, you are guaranteed not to run into a faulty PTC thermistor. The main thing here is to determine the problem, why does the backlight not work?

If you are repairing LCD, LED models, then the only difference here will be what kind of backlight is used. If it is an LCD TV, then the backlighting is produced using fluorescent or fluorescent lamps. For TVs, LED backlighting is produced using LEDs. At this point, the differences between LCD models usually end.

The breakdown can only consist in the fact that there is no power, in order to check this on an LCD TV, you can do the following with your own hands:

• open the back cover of the model;
• remove the wires connected to the matrix;
• connect the working lamp to the contacts;
• there are also LCD models in which more than one light source is provided. In this case, all sources must be tested. Just dismantle the matrix and plug your TV into the network - you can see which LED is the problem.

When a broken lamp in an LED or LCD TV is identified, it must be replaced. This stage requires maximum care from the master, as well as the manifestation of special attention. In some cases, the lamp is removed without removing the matrix, you just need to move the protective elements with a rubber gasket and pull out the lamp with a soldering iron. Similarly, it is necessary to mount a working light bulb. Now we can congratulate you - you did the repair of the LCD TV with your own hands! Just pay attention to one important nuance - the new light bulb must fully meet the parameters and dimensions of the broken one!

To repair TVs yourself, look carefully at the matrix! If there are "unhealthy" streaks here, then the breakage is in the matrix. Have a new part? Then everything is simple! You change it and turn on the TV, if it works, then you have accurately identified the breakdown.

If the reason for the breakdown of LCD TVs is the screen, then it is best to purchase new models of LCD or LED equipment. It is not recommended to change the screen of LCD and LED models, as it is impractical! This also applies to the LCD matrix.

What could be the problem with a malfunctioning plasma TV? If it is necessary to repair plasma TVs, then proceed in the same way as described above. Just adapt it to your specific case. This description can be applied to any model of plasma TV, just stock up on the necessary tools in advance.

Although today most users prefer to use plasma, many still watch programs on more outdated CRT models. Let's find out how to repair a breakdown in such TVs. Below is a step-by-step instruction that will help you repair your electron beam product with your own hands.

• If you do not turn on such a device, check first of all the fuses. In these TVs, the back is made up of panels. Therefore, it is necessary to unscrew that part of the panels. Under such panels you will find a board and the power terminals must be connected to the fuse. They are connected to a conventional incandescent lamp, or rather to its base, after which the TV must be connected to the network. In the event that your equipment is in good working order, the lamp will go out after switching on, otherwise, when the fuse has blown, it will either not work at all, or it will constantly burn.
• The diode bridge may also break. It should only be borne in mind that it is necessary to regulate and repair it only after making a dial. In this case, not only a multimeter is used, but also a product passport, which indicates the main parameters of this model.
• The most difficult breakdown in a TV with a kinescope is a posistor. To check with your own hands, you must first turn off the power circuit, and then turn it on. In this case, the lamp must be monitored. If the work lamp goes out, then it can be said that the posistor is faulty. To make repairs, it is necessary to adjust the resistance of the network and only ventures to change this part.

But not only the matter may be in the posistor, transistors and capacitors burn out in CRT models. The diagnosis of this breakdown can also be made visually. If the condensate is blackened or cracked, then we replace it with a serviceable analogue. Now you know why the TV does not work and how to fix it yourself.

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.

1. 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.
2. After removing the cover, you will see the power supply unit, consisting of several modules on the left, and the motherboard on the right.
3. 
4. 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.
5. 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.

Further, one tester probe can be attached to the body of the device, the other to the previously selected contact, and measure the voltage, having previously connected the telly to the network. In this case, the device shows 1.5 V, instead of the required 5 V. Such readings of the transformer indicate that it is working, but not at full strength. The reason may be dry condenserlocated below, or swollen - above the transformer.

To remove the parts that have become unusable, it is necessary to remove the power supply board. To do this, first disconnect all wires and the matrix cable coming from the inverter and the system board. So that in the future, after repairing the power supply, you do not get confused where what is connected, you can take a picture of them before disconnecting the wires and loops.

Now you can remove the entire LCD TV power supply by unscrewing the 4 screws. After removing it, it is very important discharge all capacitorsto avoid electric shock.

We solder the defective capacitors and replace them with new ones, observing the polarity.

The assembly of the device takes place in the reverse order: the board is screwed into place, all connectors and cables are connected, the rear panel of the unit is closed.

We again measure the voltage on the transformer of the TV's power supply (the device should turn on) and see that it has become 5v. When you unfold the repaired TV receiver, you will see that it works.

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 a 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 and lose capacity during prolonged operation, 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.

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.

The next step is to detach the control panel from the case. You do not need to remove it, you will still need it to turn on the device.

The remaining loops also need to be disconnected. Then it is necessary to remove the housing on which the electronic boards are fixed.

Before removing the matrix, unscrew front frame... We remove the matrix itself and filters, snap off the side mounts.

We connect the power and hold down a few keys to enter service menu... This will keep the lamps on for a while.

The figure below shows that after turning on the lamps, the 5th from the top turned out to be inoperative. Disconnect it and replace it with a new one - now all the lamps are on when checking.

The assembly takes place in the reverse order.

After that, you need to turn on the TV receiver and enter the service menu for reset lamp error counter... If this is not done, the device will not work. Entering the menu, you need to find the corresponding line and reset by selecting ok. Now the repair of the LCD TV set is finished. Tests show that the unit is operating normally.

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 good. 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.