DIY sony monitor repair

In detail: do-it-yourself sony monitor repair from a real master for the site my.housecope.com.

In general, it was a normal day at work, when suddenly one of the monitors of a colleague stopped working. There was no time to do it, so a new one was bought, and this one was gathering dust for half a year. But nevertheless, it was decided to repair it. At first I wanted to look for a circuit, but nevertheless I decided to disassemble it - as it turned out it was not so easy, here you can't unscrew a couple of screws - this miracle monitor is assembled on latches. so we take two flat, not sharp screwdrivers and go!

Screwdrivers should be: one wider. Another thinner blade, with one slightly pry the frame from any of the corners, starting and looking for a large latch protrusion, then push the screwdriver more there and pull the frame gently while feeding the plastic up without much effort and we get the result - the frame is removed with claps (it's okay - plastic on it's calculated).

When all the latches are defeated, we are not in a hurry to pull up - since we need to remove the two-latched handkerchief on the frame that feeds the control and power keys, and for convenience there is even a latch cable that can be removed as well.

Next, we take out the matrix assembly together with the protection casing - in which the power supply and signal processing board of the entry level is installed.

Initially I thought that there was a problem with the board, after connecting the power, the LED and the backlight turned on, and with a hiss and the smell of ozone, something rustled and blinked - the modules were protected from problems with some then unknown short circuit.

What can we do, we will look for a short one in the circuit - the forum my.housecope.com/wp-content/uploads/ext/2533 and its active user, a respected radio amateur specialist, helped me in this matter nickolay78.

Video (click to play).

The problem, by the smell, was clear - it smelled like ozone, and it was formed in the ambient air, or released when the air mixture was broken down by a high-voltage discharge. At first I thought that the matter was in the board and, just in case, warmed up the high-voltage transformer, which is combined with the multiplier, as well as the mosfet driver, the assembly of the generator control keys that controls the primary of this transformer - the problem was not solved.

I loaded one of the 2 outputs of the high-voltage converter with two series-connected capacitors 2.2 nF for 5 kV voltage, and in the other I connected the lamps in turn - the upper and the lower. As it turned out, the circuit started up normally with the upper monitor backlight lamp, but the lower one was terribly awkward and whirled in the corner, even though it tried to glow. No matter how lazy it was, I had to disassemble the monitor screen itself with the matrix. First, I unscrewed 4 screws along the frame, then a bunch of latches to disassemble the metal casing, then the same frame with a bunch of plastic latches, and all this very carefully so as not to damage the thin matrix, do not spray something on it, and not damage the matrix board, which remained on its basis - since here this company saved money and instead of 2 screws on both sides put one on the corner and clamped it well, it was not possible to unscrew it with a screwdriver at work, but it was not really necessary.

In general, the illumination lamp was removed from the edge of the reflector of the diffuser and tested separately on the table. It turns out that one of the conclusions, which is also the lamp holder, was defective and there was apparently already initially bad contact - it sparked, heating the holder body, which eventually collapsed from temperature, as a result, the wire just sparked barely holding on to the destroyed terminal, which and caused poor contact and breakdown of the circuit - that's why the protection worked.

Next, the dead lamp connector was removed, there was no new lamp for the backlight assembly, so I simply soldered the output to the wire and fixed the bay with a little glue with tape, insulated it with thick tape, assembled everything in reverse order.

Some craftsmen put LEDs on the backlight, but decided not to complicate matters. As a result, the monitor works and works for the benefit of the colleague. Special thanks for the constructive ideas and help - nickolay78... Repairs carried out redmoon.

Today I want to share with you the experience of repairing a monitor with my own hands. I repaired my old one LG Flatron 1730s... Like this:

This is a 17 "LCD monitor. I must say right away that when there is no image on the monitor, we (at work) immediately refer such copies to our electronics engineer and he deals with them, but there was an opportunity to practice 🙂

To begin with, let's understand the terminology a little: earlier, CRT monitors (CRT - Cathode Ray Tube) were in use. As the name implies, they are based on a cathode ray tube, but this is a literal translation, it is technically correct to talk about a cathode ray tube (CRT).

Here is a disassembled sample of such a "dinosaur":

Nowadays the LCD type of monitors (Liquid Crystal Display) or simply LCD is in vogue. These designs are often referred to as TFT monitors.

Although, again, if we speak correctly, then it should be like this: LCD TFT (Thin Film Transistor - screens based on thin-film transistors). TFT is simply the most common variety, more precisely, LCD (liquid crystal) display technology.

So, before we start repairing the monitor ourselves, let's consider what “symptoms” did our “patient” have? In short: there is no image on the screen... But if you look a little more closely, then various interesting details began to emerge! 🙂 When turned on, the monitor showed an image for a split second, which immediately disappeared. At the same time (judging by the sounds), the system unit of the computer itself worked properly and the operating system was loaded successfully.

After waiting for a while (sometimes 10-15 minutes), I found that the image appeared spontaneously. Repeating the experiment several times, I was convinced of this. Sometimes for this, however, you had to turn off and turn on the monitor with the "power" button on the front panel. After resuming the picture, everything worked without interruptions until the computer was turned off. The next day, history and the whole procedure were repeated again.

Moreover, I noticed an interesting feature: when the room was warm enough (the season is no longer summer) and the batteries were heated fairly, the idle time of the monitor without an image was reduced by five minutes. There was a feeling that it warms up, reaching the desired temperature regime and then works without problems.

This became especially noticeable after one day the parents (the monitor was with them) turned off the heating and the room became quite fresh. In such conditions, the image on the monitor was absent for about 20-25 minutes, and only then, when it got hot enough, did it appear.

According to my observations, the monitor behaved exactly the same as a computer with certain problems of the motherboard (capacitors that have lost capacity). If it is enough to warm up such a board (let it run or direct a heater towards it), it normally “starts up” and, quite often, works without interruptions until the computer is turned off. Naturally, this is - until a certain moment!

But at the early stage of diagnosis (before opening the patient's case), it is highly desirable for us to make the most complete picture of what is happening. According to it, we can roughly navigate in which node or element the problem is? In my case, after analyzing all of the above, I thought about the capacitors located in the power supply circuit of my monitor: we turn on - there is no image, the capacitors are warming up - it appears.

Well, it's time to test this assumption!

Let's disassemble! First, using a screwdriver, unscrew the screw that secures the bottom of the stand:

Then, - remove the corresponding screws and remove the base of the stand attachment:

Next, using a flat-tipped screwdriver, we pry the front panel of our monitor and in the direction indicated by the arrow, we begin to carefully separate it.

Slowly, we move along the perimeter of the entire matrix, gradually removing the plastic latches holding the front panel from their seats with a screwdriver.

After we disassembled the monitor (separated its front and rear parts), we see the following picture:

If the “insides” of the monitor are attached to the back panel with adhesive tape, peel it off and remove the matrix itself with the power supply and control board.

The back plastic panel remains on the table.

Everything else in the disassembled monitor looks like this:

This is how the “filling” looks in the palm of my hand:

Let's show a close-up of the panel of settings buttons that are displayed for the user.

Now, we need to disconnect the contacts connecting the cathode backlight lamps located in the monitor matrix with the inverter circuit responsible for their ignition. To do this, we remove the aluminum protective cover and see the connectors under it:

We do the same on the opposite side of the monitor's protective casing:

Disconnect the connectors from the monitor inverter to the lamps. Who cares, the cathode lamps themselves look like this:

They are covered on one side with a metal casing and are located in it in pairs. The inverter “lights up” the lamps and adjusts the intensity of their light (controls the brightness of the screen). Now, instead of lamps, LED backlights are increasingly used.

Advice: if you find that on the monitor suddenly the image is gone, take a closer look (if necessary, illuminate the screen with a flashlight). Perhaps you will notice a faint (faint) image? There are two options here: either one of the backlight lamps is out of order (in this case, the inverter simply goes “in defense” and does not supply power to them), remaining fully operational. The second option: we are dealing with a breakdown of the inverter circuit itself, which can either be repaired or replaced (in laptops, as a rule, they resort to the second option).

By the way, the laptop inverter is located, as a rule, under the front outer frame of the screen matrix (in the middle and bottom of it).

But we got distracted, we continue to repair the monitor (more precisely, for now, chick it) 🙂 So, having removed all the connecting cables and elements, we disassemble the monitor further. We open it like a shell.

Inside we see another cable connecting, protected by another casing, the matrix and monitor backlight lamps with the control board. Peel off the scotch tape up to half and see under it a flat connector with a data cable in it. We carefully remove it.

We put the matrix separately (we will not be interested in it in this repair).

This is how it looks from the back:

Taking this opportunity, I want to show you the disassembled monitor matrix (recently they tried to repair it at work). But after analysis, it became clear that it would not be possible to fix it: some of the liquid crystals on the matrix itself burned out.

In any case, I shouldn't have seen my fingers behind the surface so clearly! 🙂

The die is secured in a frame that holds and holds all of its parts together using snug plastic snaps. In order to open them, you will have to work thoroughly with a flat screwdriver.

But with the type of do-it-yourself monitor repair that we are doing now, we will be interested in another part of the design: the control board with the processor, and even more so, the power supply of our monitor. Both of them are shown in the photo below: (photo - clickable)

So, in the photo above, on the left, we have the processor board, and on the right, the power board combined with the inverter circuit. A processor board is often referred to as a scaler board (or circuit).

The scaler circuit processes the signals coming from the PC. In fact, a scaler is a multifunctional microcircuit, which includes:

microprocessor
a receiver (receiver) that receives a signal and converts it into the desired form of data, transmitted via digital interfaces for connecting a PC
an analog-to-digital converter (ADC) that converts the input analog R / G / B signals and controls the resolution of the monitor

In fact, a scaler is a microprocessor optimized for the task of image processing.

If the monitor has a frame buffer (random access memory), then work with it is also carried out through the scaler. For this, many scalers have an interface for working with dynamic memory.

But we - again distracted from the repair! Let's continue! 🙂 Let's take a close look at the monitor power combo board. We will see such an interesting picture there:

As we assumed at the very beginning, remember? We see three swollen capacitors requiring replacement. How to do it correctly is described here in this article of our site, we will not be distracted once again.

As you can see, one of the elements (capacitors) swelled not only from above, but also from below, and some of the electrolyte flowed out of it:

To replace and effectively repair the monitor, we will need to completely remove the power board from the casing. We unscrew the fastening screws, take out the power cable from the connector and take the board in our hands.

Here is a photo of her back:

I want to say right away that quite often the power board is combined with the inverter circuit on one PCB (printed circuit board). In this case, we can talk about a combination board, represented by the power supply of the monitor (Power Supply) and the inverter of the backlight (Back Light Inverter).

In my case, this is exactly the case! We see that in the photo above, the lower part of the board (separated by a red line) is, in fact, the inverter circuit of our monitor. It happens that the inverter is represented by a separate PCB, then there are three separate boards in the monitor.

Read also: DIY touch screen repair

The power supply (the upper part of our PCB) is based on the FAN7601 PWM controller microcircuit and the SSS7N60B field-effect transistor, and the inverter (its lower part) is based on the OZL68GN microcircuit and two FDS8958A transistor assemblies.

Now we can safely start repairing (replacing capacitors). We can do this by conveniently placing the structure on the table.

This is how the area of interest to us will look after removing faulty elements from it.

Let's take a close look at what nominal capacitance and voltage do we need to replace the elements soldered from the board?

We see that this is an element with a rating of 680 microfarads (mF) and a maximum voltage of 25 volts (V). In more detail about these concepts, as well as about such an important thing as maintaining the correct polarity when soldering, we talked with you in this article. So, let's not dwell on this again.

Let's just say that we have failed two 680 mF capacitors with a voltage of 25V and one at 400 mF / 25V. Since our elements are connected in parallel to the electrical circuit, we can safely use two 1000 mF capacitors instead of three capacitors with a total capacity (680 + 680 + 440 = 1800 microfarads), which will add up to the same (even greater) capacitance.

The capacitors removed from our monitor board look like this:

We continue to repair the monitor with our own hands, and now it is time to solder the new capacitors in place of the removed ones.

Since the elements are really new, they have long “legs”. After soldering in place, just carefully cut off their excess with side cutters.

As a result, we got it like this (for the sake of order, for two 1000 microfarad capacitors, I put an additional 330 mF element on the board).

Now, we carefully and carefully reassemble the monitor: fasten all the screws, connect all cables and connectors in the same way, and, as a result, we can proceed with an intermediate test run of our half-assembled structure!

Advice: there is no point in putting the entire monitor back together, because if something goes wrong, we will have to disassemble everything from the very beginning.

As you can see, the frame, signaling the absence of a connected data cable, appeared immediately. This, in this case, is a sure sign that the repair of the monitor with our own hands was successful with us! 🙂 Previously, until the malfunction was corrected, there was no image at all until it warmed up.

Mentally shaking hands with ourselves, we assemble the monitor to its original state and (for testing) we connect it with a second display to the laptop. We turn on the laptop and see that the image immediately "went" to both sources.

Q.E.D! We just repaired our monitor ourselves!

note: To find out what other types of TFT monitor malfunctions there are, follow this link.

That's all for today. I hope this article was helpful to you? See you next on the pages of our site 🙂

Here are the TOP 10 most common LCD monitor malfunctions that I felt the hard way. The fault rating was compiled according to the author's personal opinion, based on the experience of working in the service center. You can take this as a universal repair manual for almost any LCD monitor from Samsung, LG, BENQ, HP, Acer and others. Here we go.

I divided the malfunctions of LCD monitors into 10 points, but this does not mean that there are only 10 of them - there are many more, including combined and floating ones. Many of the breakdowns of LCD monitors can be repaired by hand or at home.

in general, although the power indicator may be blinking. At the same time, twitching the cable, dancing with a tambourine and other pranks do not help. Tapping the monitor with a nervous hand usually doesn't work either, so don't even try. The reason for such a malfunction of LCD monitors is most often the failure of the power supply board, if it is built into the monitor.

Recently, monitors with an external power source have become fashionable. This is good because the user can simply change the power supply in the event of a breakdown. If there is no external power source, then you will have to disassemble the monitor and look for a malfunction on the board. In most cases, it is not difficult to disassemble an LCD monitor, but you need to remember about safety.

Before fixing the poor fellow, let him stand for 10 minutes, unplugged. During this time, the high-voltage capacitor will have time to discharge. ATTENTION! DANGEROUS TO LIFE if the diode bridge and the PWM transistor burn out! In this case, the high voltage capacitor will not discharge in an acceptable time.

Therefore, EVERYONE before repairing to check the voltage on it! If a dangerous voltage remains, then the capacitor must be manually discharged through an insulated resistor of about 10 kOhm for 10 seconds. If you suddenly decide to close the terminals with a screwdriver, then keep your eyes away from sparks!

Next, we proceed to inspect the monitor power supply board and change all burned-out parts - these are usually swollen capacitors, blown fuses, transistors and other elements. It is also MANDATORY to solder the board or at least inspect the soldering under a microscope for microcracks.

From my own experience I will say - if the monitor is more than 2 years old - then 90% that there will be microcracks in the soldering, especially for LG, BenQ, Acer and Samsung monitors. The cheaper the monitor, the worse it is made at the factory. Up to the point that the active flux is not washed out - which leads to the failure of the monitor after a year or two. Yes, yes, just when the guarantee ends.

when the monitor is turned on. This miracle directly indicates to us a malfunction of the power supply.

Of course, the first step is to check the power and signal cables - they must be securely fastened in the connectors. A blinking image on the monitor tells us that the monitor backlight voltage source is constantly jumping off the operating mode.

The most common reason for this is swollen electrolytic capacitors, microcracks in the solder and a faulty TL431 microcircuit. Swollen capacitors most often cost 820 uF 16 V, they can be replaced with a larger capacity and higher voltage, for example, the cheapest and most reliable ones are Rubycon 1000 uF 25 V capacitors and Nippon 1500 uF 10 V capacitors.There is a cheaper of the decent (but always 105 degrees) Nichicon 2200 uF 25 V. Everything else will not last long.

after the time has elapsed or does not turn on immediately. In this case, again, three frequent LCD monitors malfunctions in order of frequency of occurrence - swollen electrolytes, microcracks in the board, faulty TL431 microcircuit.

With this fault, a high-frequency squeak of the backlight transformer can also be heard. It usually operates at frequencies between 30 and 150 kHz. If the mode of its operation is violated, oscillations can occur in the audible frequency range.

but the image is viewed under bright light. This immediately tells us about a malfunction of LCD monitors in terms of the backlight. In terms of the frequency of occurrence, it could be put in third place, but it has already been taken there.

Option two - either the power supply and inverter board burned out, or the backlight lamps are faulty. The latter reason is not common in modern monitors with LED backlighting. If the LEDs are backlit and fail, then only in groups.

In this case, there may be a darkening of the image in places at the edges of the monitor. It is better to start repairs with diagnostics of the power supply and inverter. An inverter is the part of the board that is responsible for the formation of a high-voltage voltage of the order of 1000 volts to power the lamps, so in no case should you try to repair the monitor under voltage. You can read about repairing the Samsung monitor power supply in my blog.

Most monitors are similar in design, so there shouldn't be any problems. At one time, monitors simply rained down with a breakdown in contact near the tip of the backlight. This is treated by the most careful disassembly of the matrix to get to the end of the lamp and solder the high voltage wires.

If the backlight itself burns out, I would suggest replacing it with the LED backlight bar that usually comes with your inverter. If you still have questions - write to me by mail or in the comments.

These are the nastiest LCD monitor malfunctions in the life of any computer technician and user, because they tell us that it's time to buy a new LCD monitor.

Why buy new? Because your pet's matrix is 90% unusable. Vertical stripes appear when the contact of the signal loop with the contacts of the matrix electrodes is broken.

This can only be cured by careful application of anisotropic adhesive tape. Without this anisotropic glue, I had a bad experience repairing a Samsung LCD TV with vertical stripes. You can also read how the Chinese repair such strips on their machines.

An easier way out of this unpleasant situation can be found if your brother-in-law friend has the same monitor lying around, but with faulty electronics. It will not be difficult to blind from two monitors of similar series and the same diagonal.

Sometimes even a power supply unit from a monitor with a larger diagonal can be adapted for a monitor with a smaller diagonal, but such experiments are risky and I do not recommend starting a fire at home. Here in someone else's villa - that's another matter ...

Their presence means that the day before, you or your relatives had a fight with the monitor because of something outrageous.

Unfortunately, household LCD monitors do not provide shockproof coatings and anyone can offend the weak. Yes, any decent poke with a sharp or blunt object into the LCD monitor matrix will make you regret it.

Even if there is a small trace or even one broken pixel, over time, the spot will begin to grow under the influence of temperature and voltage applied to the liquid crystals. Unfortunately, it will not work to restore the dead pixels of the monitor.

That is, there is a white or gray screen on the face. First, you should check the cables and try connecting the monitor to a different video source. Also check if the monitor menu is displayed on the screen.

If everything remains the same, we look closely at the power supply board. In the power supply unit of the LCD monitor, voltages of 24, 12, 5, 3.3 and 2.5 volts are usually formed. It is necessary to check with a voltmeter if everything is in order with them.

If everything is in order, then we carefully look at the video signal processing board - it is usually smaller than the power supply board. It has a microcontroller and auxiliary elements. It is necessary to check whether food comes to them. With one probe, touch the contact of the common wire (usually along the contour of the board), and with the other, go over the terminals of the microcircuits. Usually food is somewhere in the corner.

If everything is in order in the power supply, but there is no oscilloscope, then we check all the monitor loops. There should be no carbon deposits or darkening on their contacts. If you find something, clean it with isopropyl alcohol. In extreme cases, you can clean it with a needle or scalpel. Also check the ribbon cable and the board with the monitor control buttons.

If all else fails, then perhaps you are faced with a case of a failed firmware or a failure of the microcontroller. This usually happens from surges in the 220 V network or simply from aging of the elements. Usually, in such cases, you have to study special forums, but it's easier to start up for spare parts, especially if you have a familiar karate fighter fighting against objectionable LCD monitors.

This case is easily treated - you need to remove the frame or the back cover of the monitor and pull out the board with buttons. Most often, there you will see a crack in the board or in the solder.

Sometimes there are faulty buttons or a loop. A crack in the board violates the integrity of the conductors, so they need to be cleaned and soldered, and the board must be glued to strengthen the structure.

This is due to aging of the backlight lamps. According to my data, LED backlighting does not suffer from this. Deterioration of the parameters of the inverter is also possible due to aging of the constituent components.

This is often due to a bad VGA cable without an EMI suppressor - a ferrite ring. If replacing the cable does not work, then power supply interference may have entered the imaging circuits.

Usually they get rid of them schematically by using filtering capacities for power supply on the signal board. Try to replace them and write to me about the result.

This completes my wonderful rating of the TOP 10 most common LCD monitor malfunctions. Most of the breakdown data is collected from repairs of popular monitors such as Samsung, LG, BENQ, Acer, ViewSonic and Hewlett-Packard.

This rating, it seems to me, is also true for LCD TVs and laptops. What is your situation on the LCD monitor repair front? Write on the forum and in the comments.

The most common questions when disassembling LCD monitors and TVs - how to remove the frame? How do I release the latches? How to remove the plastic from the case? etc.

One of the wizards made a nice animation explaining how to disengage the latches from the chassis, so I'll leave it here - it will come in handy.

To view animation - click on the image.

Recently, monitor manufacturers are increasingly completing new monitors with external power supplies in a plastic case... I must say that this makes it easier to troubleshoot LCD monitors by replacing the power supply. But it complicates the operating mode and the repair of the power supply itself - they often overheat.

I showed how to disassemble such a body in the video below. The method is not the best, but it is fast and can be done with improvised means.

1.) The malfunction periodically occurs on monitors of different manufacturers and different diagonals. Outwardly, the malfunction looks like a periodic increase in brightness and a simultaneous deterioration of the sharpness of the image and its increase in horizontal and vertical directions. The cause of the problem is a capacitor leak in the screen signal circuit. A capacitor is connected directly to this signal and the other pin is connected to ground. The capacitance of the capacitor is about 10n. Replacing the capacitor will completely restore the monitor's functionality.

Korolev Andrey Mikhailovich

2.) Samsung 3NE Fault: Large and not adjustable horizontally. Fault detection: The TDA4850 microcircuit and the regulator itself are in good order. Checking the voltages showed no voltage on the Q408 MJE800 collector (NF / S-L, 60V, 4A, 40W, B> 750 analogs BD677, BD777, 2N6038..6039).A detailed search showed a malfunction of the protective diode D407 UF5404 (400V analogs of EGP30G, FE3H). Remedy: The diode was replaced with a Russian KD411A and the performance was restored.

3.) monitors (G50 Model 6543-302), the main malfunction is the loss of horizontal sync and a long warm-up when turned on. The reason is the drying out of a 1000x25V capacitor located between two powerful diodes in cases like KREN5.

4.) The SAMSUNG 3NE monitor does not start, the effect of overloading the power supply. Broken diode D607 RGP02-12E in the collector circuit of the key transistor or IC KA2H0880. Replaced with Soviet KD226G, the monitor worked without problems.

5.) Video monitors output voltages are 2 times higher than the norm as a result of the output from the standing vertical, horizontal scan, RGB amplifier on the kinescope board (lm1203n). The power supply is assembled for ms 3842 (dcdc converter). CAUSE breakage of the 150k resistor in the msx 3842 circuit on a small board.

12.) Brige CAE3645G Periodically appearing "twist on top" Personnel MS is in good order, electrolytes in the piping too. Diode D401 (1N4002) is faulty. Several of these were already.

13.) 17-inch ACER ASPIRE multimedia when the ambient temperature rises, the sound amplifier claps. The drawback of the project - there is a powerful transistor of the power supply next to the sound - it is eliminated by gluing a heatsink to the TDA1524 - or installing a fan from a 486 processor. Replacing the microcircuits is useless. All parts are in good working order, voltage is normal.

14.) The following malfunction may be observed in Hyundai S570 monitors: the monitor seems to work without problems, but periodically it starts to “click” (as if the protection is triggered, then demagnetization) and so on until you turn it off. After switching on, everything is again in perfect order. It can be repeated once a month, or every day. The reason is the WT60P1 processor. You can replace the processor, or you can shield it from the monitor (in most cases it helps a lot). Information for firms that carry out warranty repairs - the processor crashes due to static, and in 90% of cases this means that the monitor was plugged into an outlet without grounding, and this is a violation of the operating conditions (well, then - withdrawal from the warranty, paid repairs and etc.)

15.) Samsung 550S. External manifestation - the monitor does not turn on. Diode D406 (DG3) breaks down. I recommend changing to something thicker, for example RU4DS.

16.) Hyundai S560. External manifestation - twitching of the vertical scan, over time - resizing and disappearance. There is a reaction to tapping on the body. It is necessary to solder the frame scan m / s (I do not remember the type). Uncle Kim, when assembling, first soldered m / s, and then screwed on the radiator. The result is annular cracks in the soldering.

17.) Samsung SyncMaster 410b. Only red was displayed. The reason was the “forgetfulness” of the EEPROM 24C02 (256 * 8). The factory default brightness and contrast settings for each color have been erased. We solder it, put it on the panel. It is treated with any programmer (I have a COMPic) working with 24C (LC) 02 (we also check the validity of the EEPROM). EEPROM addresses and their meanings
————————————–
0xF6 - overall brightness (current)
0xF7 - overall contrast (current)
factory:
0xF8 - RED contrast
0xF9 - GREN contrast
0xFA - contrast by BLUE
0xFB - brightness by RED
0xFC - brightness by GREEN
0xFD - brightness by BLUE

The “normal” picture for “my” monitor turned out when all the contrast (addresses 0xF8-0xFA) was set to 0x8C, but the brightness values for each color had to be selected in the programmer until an acceptable white balance was obtained (range 0x60-0x85)

P / S Working firmware is included in the archive with firmware.

18. On many models of monitors that have been in operation for more than 4-5 years, the capacitor of the filament rectifier dries out. In this case, the monitor screen does not light up or glows very weakly (as when the cathode is worn out), and the constant component of the filament voltage is 3..5 volts.

Krasimir Krastev (Bulgaria)

19. In PREVIEV monitors, the MOS transistor for horizontal raster correction often breaks down - while the raster is compressed, there is no horizontal size adjustment and horizontal correction.

Krasimir Krastev (Bulgaria)

twenty.In PREVIEV monitors, the MOS transistor and Schottky diode in the second switching power supply to power the horizontal scan often fail. The defect manifests itself as a knocking or buzzing in the area of the pulse transformer. In this case, the power LED blinks or the power supply does not start at all.

Krasimir Krastev (Bulgaria)

21. Monitors and faxes, power supplies of which are built using microcircuits 3842, 3843, 3844 often do not start the power supply due to breakage of the triggering circuit resistor (200.50 KOhm) coming from the electrolyte of the 220 volt input rectifier. A rectifier diode and an electrolytic capacitor (20-100 microfarads) often fail in the same circuit. In this case, when the monitor is turned on, the power supply may beep or “poke”.

Krasimir Krastev (Bulgaria)

23. Monitor Viewsonic 641-1E. Periodic shutdowns. Usually, in such cases, C335 (0.22 mF) is changed, but this time the C311 capacitor (0.47 mF) was blown up. On the one hand, it was heated by a transistor radiator, and close to the capacitance, a powerful resistor.

25. Shamrock C505L
1. There is no image, the power supply is working, - 70 volts are not supplied to the output transistors of the video amplifiers. Reason: R395 break - 10 ohm
2. No on-screen menu (no power is supplied to U303 (M35043-051SP) on the video amplifier board) Reason: ZD301 Zener diode (5.18 volts) is broken through the +7 volt circuit.
3. No blue color Cause: broken diode D324 (1N4148) on the video amplifier board.
4. There is no synchronization of the image in the modes 800 * 640 and 1024 * 800 and above Cause: It is necessary to shield the control processor (C1883CT) with a normal screen (copper or brass), wires were thrown from one corner to another.

Read also: DIY phone speaker repair

26. A ViewSonic P655 monitor got for repair with a defect such that when you try to change any parameters (brightness, contrast or geometry) from the front panel upwards, the “Volume” scale is displayed on the monitor. This monitor has no built-in. ULF, no speakers. It turned out that the design of the installation is as follows: the guides are very close to the river. backplane elements. As a result, when sliding the latter along the "skis" (this can also happen during assembly at the factory) into the monitor case, with a slight left-right skew, the guides can cut off the R 710 resistor. I did not find the circuits of this model and selected the nominal value experimentally - 4K3. Menu options switching is controlled via the I2C bus and, therefore, all resistor values in the comparator are critical.

27. IBM 6314 breakdown: the image is periodically compressed vertically until it completely disappears, it is enough to solder the P701 connector - there are a lot of "cold" rations, externally (visually) the malfunction may not appear naturally - there are already several devices with such a breakdown

Hi! Get a screwdriver. It is more convenient with it. well, where you need to tighten it with a screwdriver)

What the value of the capacitor that you put in lamp connector?

Vitaly Dikarev:
In some ways you are right, BUT! Basically: everything must comply with the assembly and assembly requirements at the factory. Time passes and the equipment loses its value, the client is not ready to pay money for expensive repairs, And again. (BUT) is ready to pay (the amount of money that suits him) for the operability of the device, say, for the next couple of years. It's just not clear why this is bad? Only due to the fact that the master made his own changes to the circuitry of the device. P.S. And your argument about the wizard's desktop is not clear. WHAT IS THE DIFFERENCE TO YOU. He is comfortable, and okay. We don't care what hand you use to wipe your ass in the toilet. although it is probably right 😉 The result is important)))

Not every client will agree to replace lamps, for such work you can take 500 rubles and everyone will be happy, judging by how the monitor is stuck and by its year, it can be judged that the client does not have extra money and "complete repair" is not much of it will please.
In fact, in this monitor, it was necessary to replace 4 lamps and blow off the capacitors, but this is not cost-effective.Again, there is certainly a chance that other lamps are also running out, but upon re-supply, I think it will not be difficult to subtract the initial amount from the total, which will be calculated from the replacement price of all lamps.

And the conder is not heated. 1000r is somehow a bit too much.

+ CompsMaster but the current is small!

+ texremont Well, you never know, the voltage is high.

+ CompsMaster and why should he be

And what kind of DVD player with VGA output? I have not seen such. On the cable (it's kind of white and thin), I can assume that the farm (the component output should be, for the most part, like the synchronization needs to be redone for VGA)? But the picture looks too high quality. It is also interesting how the owners of the equipment relate to such amputations :).

People with one kidney live and there is nothing, but then you think, the lamp does not shine :)))))

I had a regular DVD with vga

+ Martin Septim is a regular DVD with VGA output, a factory cable, customers generally don't care if they amputated him, lizh would work.

Whatever one may say, this is hack. Well, there are no lamps, that's what the client should be told. Let him buy or decide what to do.

infocentrist you are a weird guy.
Check out the client or go?
You sit here, show off.

If a person arrives in a normal car where there are no shit parts and handicrafts, then of course in this car you need to use not just black electrical tape, but a native European, for example, so that there are no signs of interference.

Although, again, during installation, alarm installers disassemble the block and solder snot directly into it, because on some machines there is no other way out, or the client wants to put shit for Zhiguli on an expensive car, because when he had an agile Japanese from the 90s he had such or almost such and a normal one costs 15,000. Something shrinks in the stomach when a collective farm is molded into a good new car. And it is useless to say anything will go to another place.
The video did everything ok.
it is unnecessary to sculpt a collective farm where it is not. And where he belongs, please!

I disagree with you. The inexpediency of repair is when there is a hole through and through in the matrix. And the order of spare parts will be equal to the cost of the monitor.
And here everything is there, but too lazy to order, too lazy to wait. 10 is inappropriate, you need 1. Well, excuses are unrealistic. As if repairs are underway at the expense of the workshop. The client pays, the client receives.
One master otmazyvaet another)) I understand :) I just would have made a scandal)
I do not swear, you are a pro in your field. So, I express my opinion.

+ infocentrist There is such a concept: Feasibility of repair (this is when, for example, the cost of repair is equal to or exceeds the cost of the product)
In this case, the repair was not advisable, and Eugene got out of the situation, extended the life of the monitor, everyone is happy! What's wrong is.

And here it is. Well, you must miss so much))