Do-it-yourself erisson 1401 TV repair

Erisson 2120 chassis 3S10
Cannot tune to channels. When automatically tuning to a station, there is no synchronization both by lines and by frames, the picture is b / w (it does not remember the channels and simply skips them).
On examination, it turned out that the L301 throttle was not drilled and the R325 burnt parallel to it. At first I thought that there was a memory failure, but when I entered the service (MENU-> AV-> ANAL), I did not find any deviations.
After checking the piping of the TDKS and the STV2248C video processor, I came to the conclusion that the latter was malfunctioning. After replacing the STV2248C, the device started working. PS: put a percentage on the socket because of the large number of defects on sale (luck smiled at me the second time). Whoever has “lit” 100 µF in position C009A - change to 10 µF to prevent memory failures in the future.

Erisson 1401 chassis MDY5
The power supply unit is going to the pediment. Power + V = 180 volts at a rate of 110 volts. Leaking transistor Q904 2SC1815. After replacing it and replacing R915 1.5Ω, standing along the + B circuit, everything returned to normal.

Erisson 1401 chassis MDY6
When you turn on the TV, the LED lights up, the screen is dark, there is no sound. The power supply unit at the + B output is twice as high. electrolytes С917, 922, 924, 403 are inflated. defective Q406 2SB764. I connect a 220V 60W lamp to + 110v. When the power supply unit is turned on, it goes into spacing, after a while the voltage stabilizes. In the power supply unit, I replaced the Q904 2SC1815, turned on the power supply network, it works great. Replaced IC801 LA42351 sound is. Thanks to the people who share their information on the site.

Erisson 1430
When working, the brightness floats, when very bright scenes appear, it goes to the duty room. If you lower the gain or lower the brightness, it works fine. checking the OTL circuit did not give any results. The reason turned out to be much simpler - a break in the filter capacitor at +112 V. After replacing the TV, it worked fine.

Erisson 1401 composition LC863532 LA76818 LA78040N
Defect - with an ideal picture, the jitter of service information (menu, channel numbers, etc., etc.) Replacing the C432 (in the personnel voltage boost) solved the issue.

Erisson CTV-3410 - does not turn on
Composition of NN5198K, AN5539, AN5274, HOT-2SD2500, BP-C4429
Failure of the cyclic bp as a result, the NOT was broken due to the increased voltage, replaced 2 - litas 47/25, 2200/35 also burned out PR901 according to the scheme is designated as 2-opposite on the diode written 300V from it 2-pins and a disk are left. on position C950, R950, ZD988 but no denominations.
R439 turned out to be faulty, its value became 2.1 Ohm, although it was 1 Ohm
put 0.56 Ohm bodies stopped off. C848 was swollen, the AN5274 sound was also out of order. Solved.
Sent by Sergey 100

Erisson S14 chassis 3Y11
LC863328C-55W0, LA76810A
It turns on, a green screen with the inscription ERISSON, gradually (within 5 seconds) the brightness increases, the screen fills with green without LOH. If you reduce the Screen - the screen darkens, the inscription is green. There is no sound, it reacts to switching channels. At the output of the VP - R - 2.2V G - 4.3B B - 2.5V.
To eliminate it, it is necessary to replace the LA76810A.

Erisson 1406 chassis 3Y11
STRG-6653
when the power supply is applied, the power supply starts for 2 seconds and goes to stop. Everything was sorted out in accordance with the recommendations for both the primary and the secondary, but the jamb was found R 612 the optocoupler power control circuit increased the rating from100 to 158kom

Erisson 21F1 chassis 3P51
TDA9381PS / N3 / 3, PSU - CQ0765RT
Came with a failure to start the power supply unit. I found a C615 1500/2 KV capacitor that was darkened with a crack, but it still didn’t start up, I replaced the micr. in the power supply unit CQ0765RT, the TV started, everything worked fine, but after turning off the power button, the power supply unit did not start again, I checked the litas. After a long idle time, the TV turned on, but after turning off the power button, again there is no power supply start. When it did not start, there was no voltage on the microcircuit to start 18v, I replaced the D614 zener diode with 18v and everything went, although before that the zener diode was checked as a whole, and after replacement checked, also normal, whorled it can be seen under voltage and planted 18v

Erisson 2120 chassis 3S10.
On HF it works fine. On AV - there is no signal. If you turn off the “blue background” function, the signal from AV goes, but there is no synchronization.
Replacing the video processor STV2248C solved the problem.
As it turned out later, the client connected TRICOLOR to hot.

Erisson 2109 chassis 3Y11
B.P. - STRG-6653
The power supply starts for a moment with overestimated output voltages (instead of 110v -140m, instead of 20v-25v, 5v is normal), and immediately goes into protection (at the outputs = 0 v) - The problem was solved by replacing the interrupted resistor R642 = 100 ohm in the optocoupler circuit ...

Erisson 21UF20 chassis 3P61E
I flashed TDKC BSC29-3807B and dragged off the TDA4865AF frame chip. There was no native TDKS. The client was literally breathing down the back of his head, so he had to improvise from what happened. The BSC25-N0809A from AVEST 54ТЦ-04 was successfully installed with a minor modification, which consisted in a home winding on the core of an additional winding of 10 turns connected to the 7 and 9 TDKS terminals. Instead of TDA4865AF, the TDA4863AJ quietly came up.
Then I read on the Internet that the BSC29-3807B has a direct analogue - 6174V-6006M (n). This means that a reverse replacement at AVESTA is possible without alteration.

Erisson 2103 chassis BN37
When the TV is turned on, the brightness starts to increase and the power supply protection is activated. The problem was solved by replacing the Q504 2SA1015 transistor, which was broken through to-e and completely opened the cathodes.

Erisson 25F2 chassis BN88
When turned on, the relay cyclically clicks on B +, power stabilization is violated. Banally increased (up to 40 ohms) its resistance R902 = 1.5 ohm 5w, in the emitter Q904 (2SC4429) B.P.

Erisson 2103 chassis E3701-022010A2
I came with a complaint: it stupidly reacts to the remote control, no more than 1.5 m. I noticed the photodetector and the LED next to it less than 1 cm. I put a black partition between them. From 5m it responds perfectly.

Erisson 21SF10 chassis 3Y18
The vertical size spontaneously increased, the adjustment in the service did not help for long, the signal disappeared until you restart the TV.
I installed a new memory with a working firmware, no failures.

Erisson 1401 chassis MDY5
BP - clearly gave out overestimated voltages. On the circuit: + 26V was + 41V. Faulty: pos: IC401 - LA78040N; pos: Q406 - 2SB764; Replaced litas: pos: C922 - 1000 / 35V; pos: C420 - 330 / 35V;
The culprit of the malfunction turned out to be: RP901 1k - installed in the stabilization circuit (burnout). Replaced and litas: pos: С934-С933 47 / 50V

ERISSON 21SF40
Composition: 8896CSNG7E18, LA78041, 24C16A.
Fault: the image is shifted to the right by 3 centimeters, on the left there is a “torn” edge. The culprit - R466 10k in the cliff, stands from the 7th leg of the TDKS ABL, then through R227, VD210 at 27 pins.

Erisson1401 chassis E3701-054070A
Does not leave standby mode. (From the words of the owner: when turned on, the picture either immediately appeared normal or was compressed horizontally, after some work it could be restored.) Upon examination, an incorrect Q406 was revealed (the key for powering the IC401 (LA78040) KR, and the pre-output stage of the horizontal scan), as well as changed in BP e-you C933, C934. After that, the TV turned ON-OFF-ON-OFF, the screen did not have time to light up. The KR became very hot and again the breakdown of Q406 (all the voltage from the power supply unit is normal). When replacing the KR (LA78040) and C432- (voltage boost), everything remains the same. After a long study, the turn-to-turn personnel winding turned out to be faulty, during external examination it was not revealed, and the tester R = 3.4 Ohm. Compared to a similar operating system on which this chassis is working properly, R = 16 ohms.

Erisson 2106 chassis 3Y11
After a thunderstorm. Changed memory, did not save data.
Unpleasant jammed sound. Illegible speech, especially on Russia-1.
The ULF works purely without distortion; the sound standards are really switchable.
Defective video percent. LA 76810A.
I did without replacement. I used UPCHZ-2. I spoke beautifully.

Erisson 2120 chassis 3Y11
hiss instead of sound on the 6.5M standard, the effect is as if the sound standard is not turned on correctly. The reason turned out to be a video processor: LA76810A

Erisson 29F2 chassis BN88
https://my.housecope.com/wp-content/uploads/ext/2254/section1/topic118029.html
It turns on, the line starts and immediately off - the relay opens.
Blame Q405 - A1320.

Erisson 21UF20 chassis 3P66
I could not start at full strength, there is a horizontal bar on the screen when adding a screen for a few seconds and restarting. Instead of 5V on 3.45V processor. The culprit is S8050, 5V processor power supply. Phoned as serviceable.

ERISSON 29F5 BN88
Clicks inside (according to the client), breakout of bsc25-0101c output. It is far to the store (160 km), and there are plenty of samsungs with a “sweet couple” in the firewood. TDKS was installed with SCT-11 FCV-20A001 with a slight re-routing and the values ​​of R426-2.2om / R427-4.7om were changed, and the heat was corrected (1st). This year, such devices hit 2 times, in the first case, another percent was killed. I forgot to solder the ABL wire in the re-routing photo. (Ed. By gilan)

LG863324A processor,
memory ST24C04.
tuner EWT-5V3S32-E08W

When turned on, the network button or remote control can immediately turn on and work without any remarks. But it may not turn on for a long time. If you turn off the network and turn it on again, then everything repeats. It can turn on, maybe not.
During the manifestation of a malfunction, the indicator dims by half, although usually the transition from worker and vice versa from duty to worker in this model, the indicator does not react.
In memory and in the process, the 5-volt voltage drops to 2.72V.
Sometimes in this state, you can turn it on from the control panel, the sound and sound of the last state appears, but there is no reaction to the remote control.
Memory microchip malfunction. Replacement, firmware solved the problem.

Erisson TVs have “bugs”. Previously, “bugs” were called errors and breakdowns in telegraph and telephone systems, as well as in radar electronics. Later, this professional slang word migrated into the vocabulary of programmers. So in modern widespread electronics there is also “bugs”- errors in design and construction.

One very common malfunction in CRT TVs can be called a "bug" Erisson... This malfunction manifests itself after a year or two from the moment the device began to be used and the cause of further malfunction is the transistor in the frame scan circuits. Frame scanning in CRT televisions serves to form a vertical image and controls the electron beam in the CRT.

As a rule, a "bug" manifests itself as follows:

The TV does not switch from standby to working.

Such a manifestation of the defect is due to the fact that in the event of a malfunction of the frame scan units in the TV, the protection against the kinescope burn-through is activated.

CRT burn-through Is when the screen has a bright horizontal bar in the middle of the screen. In this case, all the energy of the electron beam is focused on this narrow band, and as a result of this, the phosphor of the kinescope can be burned out in the place where the electron beam hits.

If you leave a TV with such a defect on for a long time, then later in the place where there was a horizontal strip there will be a section with a lower luminous efficacy (burnt-out phosphor) - the picture tube will be damaged. To avoid this, modern TVs have built-in protection against kinescope burn-through and the TV simply does not switch from standby (sleep) mode to working mode.

On the CRT screen, there is a bright horizontal line in the middle of the screen.

In this case, the protection against burn-through of the kinescope does not work, since the electric circuits of the frame scan are working, but the faulty elements still partially fulfill their function and the protection system does not “see” that a malfunction has occurred. Therefore, a bright horizontal stripe appears on the screen.

If there is a horizontal bar on the screen, then try to turn off the faulty TV as soon as possible in order to prevent damage to the kinescope.

It was with such a malfunction that the TV got on the repair table. Erisson (model 1401, manufacturer Telebalt LLC, Kaliningrad). The TV did not switch from standby to working... The cause of the malfunction was a transistor. 2SB764 with broken transition E–TO... The resistance between the emitter and collector leads was zero. This is what caused the protection against burn-through of the kinescope to operate.

On the circuit board, the 2SB764 transistor is designated under the serial number Q406... The transistor itself is located next to the microcircuit LA78040N... The LA78040N microcircuit is the main amplifying element in the frame scan circuits. A deflection coil is connected vertically to this microcircuit.

After replacing the 2SB764 transistor with a new one, the TV began to turn on, but a bright strip formed on the screen in the middle of the TV picture, and the image at the top of the screen was nonlinearly elongated. Teleradiomechanics call such a defect “bloat”. When turning vertically, the image is as if superimposed - wraps up... The photo shows a twist formed after replacing the 2SB764 transistor.

In addition to the resulting vertical twist, the new 2SB764 transistor got very hot during TV operation - there was still some faulty part in the circuit, leading to overheating of the replaced transistor. When turned on, the TV did not turn on for a long time, and the image first appeared in a narrow strip in the middle and then slowly expanded to full screen.

After a short search, it turned out that in a switching power supply, an electrolytic capacitor (47 microfarads. 50 V.) has a small capacity, which amounted to 19 microfarad. instead of the required 47. The capacitor has a reference designation on the circuit board under the number C933.

If you encounter a similar malfunction, be sure to check this capacitor.

After replacing the capacitor in the power supply, the image began to appear faster, but despite this, the image, when turned on, unfolded as if from a pillow. Transistor 2SB764 still very hot... After a couple of switching on the TV, the transistor struck again, despite the fact that a small radiator was installed on the transistor. So several unsuccessful attempts were made to replace the 2SB764, which resulted in 2 damaged 2SB764 transistors. The latter went out of order without even working for a minute ...

If you wander on the Internet on the electronics repair forums, you can find recommendations for replacing the 2SB764 transistor with a more powerful transistor 2SB772 in brand TVs Erisson, in order to exclude the breakdown of the 2SB764 transistor and the repeated failure of the TV - relapse.

In practice, it is not always possible to find a 2SB772 transistor. In this case, you can use a domestic transistor KT814... It, like 2SB764, 2SB772 has the structure P-N-P and the parameters are close to 2SB772.

After installing the domestic KT814 instead of the imported 2SB764, the TV began to work properly - the “twist” disappeared, and the excessive heating of the transistor stopped.

When repairing a TV Erisson 1401 with the described malfunction, first of all, check the 2SB764 transistor (Q406), if possible, replace it with more powerful analogs 2SB772, KT814. Also, an analogue of the 2SB764 transistor is 2SB985which can also be used as a replacement. You should check the capacitor in the switching power supply unit number C933. As mentioned, it may have a capacity loss.

A similar malfunction was observed in Erisson 2102... The already known transistor 2SB764 turned out to be faulty.

Darkening was observed on the circuit board around the 2SB764 transistor - evidence of excessive heating of the transistor. Due to overheating, the 2SB764 fails. Burnout of this transistor in TVs Erisson Is an explicit “bug”. The Erisson 2102 was restored by replacing the faulty 2SB764 with an analogue 2SB985.

The pinout of the terminals of the transistors 2SB772, 2SB764, 2SB985, KT814 is shown in the figures.

Good evening! For more than a year (with interruptions) I have been repairing Erisson 1401 TV for conversion into a video monitor. The manifestation of the malfunction is as follows: unstable start, if it starts, the raster is dark, defocused, narrowed horizontally, slightly enlarged vertically (similar to a low anode one). Supply voltage p. about 70V. Only the power transistor BP is heated (strongly), the lowercase and personnel are completely cold. I did not find any shorts in the PSU loads. On the other rectifier, the PSU is about 4.5V. Sometimes the box tries to turn on, but does not turn on (with + B disabled). 4.5V becomes + 8V (+ V is not possible to measure, because there is a relay before the diode, i.e. in a pulse circuit where the multimeter is wildly lying), most likely, the PSU goes into gear and the X-ray protection is triggered. There is no reaction to tapping.

In general, the circuit is similar to the BN6R, in many respects the same, but the power supply is different, the primary is assembled on 4 transistors, of which one (power) is field-effect. There are two 47uF 50V conduits, in turn a good one was plugged into each, but the result is zero. There is a place for an optocoupler on the board (the wiring is similar to the BN6R), but it and its piping are missing from the factory.

Compound:
Marking: E3701-032010A 07.21-2003
Control: TS4A-07-1003 8821CPNG5CR2
HR: STV9302A
Video input switch: TC4052BP
Memory: Atmel 446
TDKS: Konka BSC 25-0217
CRT: Hitachi 37SX110Y22-DC11
TMS: BTC-1939WH
TPI: BCK-4209WH
Assembly: Telebalt, 2005
The + V voltage in the duty room is turned off by the relay, the relay is up to the diode. There are no relays on the BN6R diagram, as well as “extra” transistors in the power supply unit.

Interested in the possible causes of the malfunction, or the diagram.

Good afternoon, in smart TV mode (on the main screen of the smart), the Source button does not work, to switch to another signal source, you have to restore the system, then the smart menu does not turn on, but the TV mode turns on immediately, and the button works, but when you press HOME button, and go to the smart menu, I can't switch back to TV

Most likely, for this model, these are programmers' flaws. However, the Source button is in Smart mode and should not work until you exit it.

erisson 32les73 - when turned on, the LED turns green, the screen blinks with the splash screen for a second and goes out, the LED remains green, can you tell me what could be? Thanks in advance!

The matrix backlight is probably faulty.

Please say I turn on the TV Erison works all the rules and then it turns off itself, which heats up in it and it turns off when cold air gets on it, then it works fine

It is necessary to disassemble and look, probably swollen capacitors.

TV erisson 21f2 turns on cloudy screen the image is slightly visible, white stripes on the diagonal and after 5-10 seconds. turns off. Please tell me what parts need to be replaced !?

Check the power supply of video amplifiers, to replace C425, C520.

Please help, erisson 39LES65, turns off completely after 5 minutes of operation, then the red indicator turns on. I turn it on again and still, 5 minutes of viewing and off

21uf22, after tuning the channels, one channel was tuned to all.

Errison 21UF11. There was a lock (a key in the left corner), pressed the buttons on the remote control, wrote "Turn on in 30 seconds." The TV turned off, now it does not turn on, the duty room diode is on (it does not respond to the buttons on the remote control and on the TV itself.

Tell me, plz. A very strange problem. Erisson 24LEE31T2 TV, does not turn off with the remote control. Rather, it goes into standby mode, but after 1-2 seconds it spontaneously leaves it to work. This happens several times (2-4) in a row, while he calms down in standby mode.

If the TV did not switch from standby to working mode in the first seconds, then this never happens.

We need diagnostics. It can be either a power supply failure or main.

Hello! Erisson TV 21f2, Before that, it turned on and worked normally, then no, there was a hum in the speakers but did not start, now it turns on but there is no image, when you spin the accelerator on TDX, stripes with a white background appear on the screen. What to do?

Check the voltages of the secondary and TDKS.

there is a lot of red on the erisson 2108 TV, what is the reason?

Malfunction of the video amplifier or picture tube.

I ask for help if possible, erisson 20lj02, it turns on, the green LED lights up, there is no backlight. In the inverter, there is a voltage of 12 V on electrolytes 220 x25, silence on the TL494 PWM.

It is necessary to check exactly at pin 12 of the IC. If it is not there, look for where it is lost (a 1-2 ohm resistor may break) and then look for the causes of the break.

I blunt a little, there is a supply voltage at the 12th, there is no 5v reference voltage at pin 14.

Do you have a pinout for the inverter connector? what voltages should come from the board?

It is necessary to check all the important details in the inverter, power transistors, replace the microcircuit, but the metric has nothing to do with it.

Erisson 24LEB15, When you exit the standby mode, the LED turns green, the backlight flashes for a split second and there is no reaction, there is. De-energized about 2 stands. The clock turns on normally until it falls asleep or turns it off from the remote control.

What can I say, first you need to "examine".

Erisson 39les65 TV
Can't find USB signal switching. Power comes to the flash drive, and only ATV, that is, television, works in the list of signals.

And that there are no instructions? Flash drive as formatted in FAT or NTFS.Only FAT support is possible.

Checked it out. The flash drive is formatted in FAT32. By the way, when I just bought this TV, it read a portable disc with films. True, they walked on a small screen, like a probe. Now the disk cannot be found either. There is an instruction.

If you stopped seeing the disk, and now the USB flash drive, then there is probably a problem with the power supply of external devices. It can be either undervoltage (less) or ripple of the 5V stabilizer.

power supply, a la RECOR. The capacity is close to the radiator, the ESR is poor. Nik_Drozd

3259. ERISSON 1401. Defect: does not leave standby mode, does not respond to any remote control,
nor on the panel buttons. The reason was the absence of + 27V voltage due to the breakdown of BE Q406
(2SB764).

2804. Erisson 1406 Defect: does not turn on (no standby mode, fuse intact).
Mains electrolytic capacitor voltage is OK. Outwardly, everything resembles
B / P on STR-S, when there is no start after lightning. Replacing STR-G6653 nothing
gave. The reason turned out to be in the disk capacitor C606: 1nF (its nominal value was
6nF. ) Yuri (Bryansk, Bezhitsa)

3321. Erisson 1460. Defect: does not turn on, the standby indicator does not light up.
The reason was in the breakdown of the C615 (2200p), in the second of the power supply. Vladimir. town of Iskitim.

2479. ERISSON 1465, chassis 3Y01. Defect: no color in SECAM, black and white in
order, switching the color system does not give a result. Sekam is made on a microcircuit

• 

Is your TV, radio, mobile phone or kettle broken? And you want to create a new topic about this in this forum?

First of all, think about this: imagine that your father / son / brother has an appendicitis pain and you know from the symptoms that it is just appendicitis, but there is no experience of cutting it out, as well as the tool. And you turn on your computer, access the Internet on a medical site with the question: "Help to cut out appendicitis." Do you understand the absurdity of the whole situation? Even if they answer you, it is worth considering factors such as the patient's diabetes, allergies to anesthesia and other medical nuances. I think no one does this in real life and will risk trusting the life of their loved ones with advice from the Internet.

The same is in the repair of radio equipment, although of course these are all the material benefits of modern civilization and in case of unsuccessful repairs, you can always buy a new LCD TV, cell phone, iPAD or computer. And for the repair of such equipment, at least it is necessary to have the appropriate measuring (oscilloscope, multimeter, generator, etc.) and soldering equipment (hair dryer, SMD-hot tweezers, etc.), a schematic diagram, not to mention the necessary knowledge and repair experience.

Let's consider a situation if you are a beginner / advanced radio amateur soldering all sorts of electronic gizmos and having some of the necessary tools. You create an appropriate thread on the repair forum with a short description of “patient symptoms”, ie. for example “Samsung LE40R81B TV does not turn on”. So what? Yes, there can be a lot of reasons for not switching on - from malfunctions in the power system, problems with the processor or flashing firmware in the EEPROM memory.
More advanced users can find the blackened element on the board and attach a photo to the post. However, keep in mind that you are replacing this radio element with the same one - it is not yet a fact that your equipment will work. As a rule, something caused the combustion of this element and it could “pull” a couple of other elements along with it, not to mention the fact that it is quite difficult for a non-professional to find a burned-out m / s. Plus, in modern equipment, SMD radioelements are almost everywhere used; The subsequent restoration of which will be very, very problematic.

The purpose of this post is not any PR of repair shops, but I want to convey to you that sometimes self-repair can be more expensive than taking it to a professional workshop. Although, of course, this is your money and what is better or more risky is up to you.

If you nevertheless decide that you are able to repair the radio equipment on your own, then when creating a post, be sure to indicate the full name of the device, modification, year of manufacture, country of origin and other detailed information. If there is a diagram, then attach it to the post or give a link to the source. Write down how long the symptoms have been manifesting, whether there were surges in the supply voltage network, whether there was a repair before that, what was done, what was checked, voltage measurements, oscillograms, etc. From a photo of a motherboard, as a rule, there is little sense, from a photo of a motherboard taken on a mobile phone there is no sense at all. Telepaths live in other forums.
Before creating a post, be sure to use the search on the forum and on the Internet. Read the relevant topics in the subsections, perhaps your problem is typical and has already been discussed. Be sure to read the article Repair strategy

The format of your post should be as follows:

Topics with the title “Help fix the Sony TV” with the content “broken” and a couple of blurred photos of the unscrewed back cover, taken with the 7th iPhone, at night, with a resolution of 8000x6000 pixels are immediately deleted. The more information you post about the breakdown, the more chances you will get a competent answer. Understand that the forum is a system of gratuitous mutual assistance for solving problems and if you are dismissive of writing your post and do not follow the above tips, then the answers to it will be appropriate, if anyone wants to answer at all. Also keep in mind that no one should answer instantly or during, say, a day, no need to write after 2 hours “That no one can help”, etc. In this case, the topic will be deleted immediately.
You should make every effort to find a breakdown on your own before you get stumped and decide to go to the forum. If you outline the entire process of finding a breakdown in your topic, then the chance of getting help from a highly qualified specialist will be very great.

If you decide to take your broken equipment to the nearest workshop, but do not know where, then perhaps our online cartographic service will help you: workshops on the map (on the left, press all buttons except “Workshops”). You can leave and view user reviews for workshops.

For repairmen and workshops: you can add your services to the map. Find your object on the map from the satellite and click on it with the left mouse button. In the field “Object type:” do not forget to change to “Equipment repair”. Adding is absolutely free! All objects are checked and moderated. A discussion of the service is here.

composition: power supply-D2498, lowercase-TT2140, LA7804ON, LC423515ZX2, LC863532C, LA76818A
there are voltages on the secondary, it does not react to an attempt to turn on (from the panel, from the remote control), a week ago it was with the same defect, after replacing the electrolytes in the power supply unit it started working. in a week return.

What is the voltage on the collector of the line transistor?

What is the voltage on the collector of the line transistor?

Pulse, with an amplitude of 1100v.

Are we going to repair it or let it work?
"A person cannot be helped against his will." G. Pomerants

Pulse, with an amplitude of 1100v.

When the horizontal scan works, I mean that their resistor often burns out in the power supply of the horizontal.

What is the voltage on the collector of the line transistor?

Well, look for why there is no start: line transistors, power supply, TMS.

on B + is also 110 V, instead of 180 - 110 V, ABL-11 volts

: Co_ol: Not all measuring devices can withstand such savings, adnaka.

Is it possible to put the experience of many years into your head in two minutes?
"No amount of reasoning is able to show a person a path that he does not want to see." Romain Rolland

Hi sa — shok! And like quartz, I tried to change or look at the generation.

Hi sa — shok! And like quartz, I tried to change or look at the generation.

And yet, somewhere, from two weeks ago, I did such 2 things, both had a memory problem, they also did not leave the bowls.

Not all measuring devices can withstand such savets, adnaka.

Withstand the best and most reliable 🙂 sa — shok On the 8th output of the controller, +5 V. From output 2 through three transistors, the scan is turned on by supplying power from the power supply to the first winding of the tms. Checked on the call 401 does the power appear? On pin 2, does it change?

This article examines the budget UBM chassis of Chinese manufacturers, on which TV models of the models indicated in the title of the article with diagonals of 21, 25 and 29 inches CRTs are produced. The chassis is based on the PANASONIC NN5199K multifunctional video processor.

Main technical characteristics

ERISSON TVs assembled on the UBM chassis have the following specifications:

• CRT diagonal: 21, 25, 29 inches (see Table 3);

- from RF input: PAL BG / DK, SECAM BG / DK;

- from LF input: PAL / SECAM / NTSC 3.58 / 4.43;

• TV channels: VHF-L (E2-S10), VHF-H (E5-S41), UHF (E21-E69);

• line scan frequency: 15625/15750 Hz;

• vertical scan frequency: 50/60 Hz;

• output sound power (F = 1 kHz, THD = 10%) - 2 × 3 W;

• power supply: alternating voltage 100. 260 V, 50/60 Hz.

• power consumption in operating mode - 80/150/160 W (respectively, for TV with picture tubes 21/25/29 inches);

• power consumption in standby mode - no more than 15 W.

Basic electrical diagram

The schematic diagram of the UBM TV chassis is shown in Fig. 1. The chassis under consideration is implemented on the basis of an IC601 microcontroller (MC) of the KS88C8424 type from SAMSUNG and an IC201 video processor of the NN5199K type from PANASONIC. A detailed description of these microcircuits has already been repeatedly given, for example, in [1], therefore in this material we will only give the purpose of the pins of these microcircuits in relation to the chassis in question.

The IC201 video processor (NN5198 or NN5199) provides video signal processing in the luminance and chrominance channels, limiting the brightness and contrast of the image when the kinescope beam current is exceeded, inserting OSD signals, teletext and external RGB signals into the image. The video processor is controlled by a microcontroller via the I 2 C bus.

The pin assignment of the IC201 microcircuit is shown in table. one.

Table 1. Purpose of the pins of the NN5199K video processor

I 2 C interface clock bus

Beam current limiting signal input

Blanking (Insert) RGB signal input

External video inputs R, G, B

Video signal outputs R, G, B

Chroma block 4.43 MHz crystal resonator

External video / chroma input

IF PLL filter

Audio detector output

Detector decoupling filter

Chroma block quartz resonator

Timing unit supply voltage 6.2 V

Line scan trigger pulse output

PLL filter 1 synchronization block

Audio pre-emphasis filter

Frame sawtooth pulse output

Frame sync AGC filter

Gate pulse output

I 2 C interface data bus

Line scan feedback input

MK IC201 provides control of the TV units via the I 2 C bus, receiving commands from the front panel keyboard and from the remote control (RC), generating OSD signals on the TV screen. In addition, individual signals are used to control the tuner, select signal sources, mute mode (MUTE), and control the power supply. To store the TV settings, an electrically erasable reprogrammed ROM (EEPROM) IC602 of the 24C04A type is used.

The purpose of the MC terminals is given in table. 2.

Table 2. Purpose of the conclusions of the KS88C8424 microcontroller

Tuner tuning voltage

I 2 C interface clock bus

I 2 C interface data bus

Volume control output

Signal to enable the filter 3.19 MHz in the IF circuit

EEPROM write enable output

Front panel keyboard inputs

External control input (programming port)

Test mode enable input

Video blocking output

Selecting the tuner reception band

Power supply control

Generator control input OSD

Line sync input

Frame sync input

Leads for connecting the LC circuit of the generator

Leads for connecting a quartz resonator 8 MHz

IC reset signal input

AV switch control output

AV / TV switch control output

X-ray voltage protection input

Line scan protection input

Nodes of vertical and line scanning are made according to typical schemes and also do not need a detailed description. Since most of the faults occur in the power supply, we will consider its circuit in more detail, especially since it is implemented on discrete elements.

This unit is made according to the scheme of a self-oscillating blocking generator on a Q904 transistor and a T901 transformer. The positive feedback circuit consisting of winding 9-10 T904 and elements C911, R912 controls the switching of the power transistor Q901. The parameters of this circuit determine the operating frequency of the blocking generator. To stabilize the output voltages, an error signal amplifier is used on the elements Q901, ZD901 and a control pulse generator Q901 Q903, from the output of which the signal is fed to the base circuit Q904. The voltage of the winding 11-12 T901 through the rectifier D901 C910 is fed to the error amplifier and is used to monitor the output voltages. Output voltages are stabilized by changing the width of the power switch control pulses.

In some TV models, elements are installed that are circled on the schematic diagram of the source with a dashed line. This is an automatic switch for mains voltage 220/110 V, which includes an IC950 controller (AVS1BCP08) and an IC951 triac (AVS08C8, im = ± 500 V, I = 5 A) from STMicroelectronics. The input mains voltage is monitored by pin. 8 IC950, the microcircuit is powered by pin. 7 (-9 V, 1 mA). The internal generator of the microcircuit (pin 2, 3) operates at a frequency of about 42.46 kHz. When the mains voltage drops to 110V, the controller opens the IC951 triac and the mains bridge rectifier switches to half-wave mode with voltage doubling.

Secondary rectifiers of the source are made according to one-half-one circuit. At the output of the source, voltages + B (110.135 V, depending on the diagonal of the picture tube), +18, +6.3 and +5 V.

In standby mode, the + B voltage is disconnected from the horizontal scan using the contacts of the RLY901 relay, which is controlled by the POWER signal from the pin. 20 of the IC601 microcontroller through a key on the Q601 transistor. The standby voltage of +5 V for the MK power supply is formed by the Q607 ZD606 stabilizer, which is powered by the +18 V circuit. An alarm in the horizontal scanning circuit is controlled by the node on the Q406, ZD409 elements.

This is a step-down stabilizer, in normal mode it generates a voltage of +5 V, which is fed to the control input - pin. 42 IC601. In emergency mode, when the + V voltage is overestimated, the reference voltage of the ZD409 zener diode is also overestimated, as a result it “breaks through” and the stabilizer turns off. Low potential for pin. 42 IC601 is a sign of an emergency, and MK is a high level of the POWER signal on the pin. 20 disconnects the + V voltage from the horizontal scan.

Next, we will consider the procedure for adjusting the UMB chassis, which must be performed after repair (replacement) of faulty components.

Service menu and electrical adjustment of the UBM chassis

Line scan supply voltage regulation + B

1. The TV is switched on in the operating mode, a test signal “color stripes” is fed to its input (antenna or LF) and it is warmed up for 15.20 minutes.

2. Select “Natural” picture mode on the user menu.

3. Connect a digital voltmeter between the positive terminal of capacitor C416 and ground.

4. Variable resistor VR901 set voltage + V ± 0.3 V. In table. 3 shows the voltage values ​​+ V, depending on the type of kinescope.