Voltage of unstable + B Tv Telefunken TK2525STX
In addition to what is indicated by the Master MIguel, you can: 1.- remove the flyback and the hot, place a bulb of 75w from the b + to ground and check the voltage, this has to be stable. If this is not the case, it has a filtering problem, as Maestro Miguel comments.- to adjust the screen in a practical way, just place the TV in black and white and adjust the focus and the screen the best you can see, this is because As time goes by, the kinescope loses a lot of its nitides. greetings everyone.
Thank you Felipe for answering and change the capacitors are two one of 220uf 160v and 100uf 160v is still the same but I was measuring voltages without the transistor hor and the voltage of + B stays in 134v I will see if I get the lamp of 75w to do the test , the screen looks and listens well greetings.
The power supply test to be valid, must have a load. you can place a 75w bulb or a 680 ohms 20w resistor. Regards.
You can try that lamp, we use a resistance of 680 ohms 20w, for the reason that where I live there are no lights of those old ones. Now with these new ones we have never tried. I repeat, we are accustomed to resistance, and in switched sources it gives us a better result because it does not cause the source too much load. Try and comment. The voltage has to be stable. regards
We remove the flyback and the hot, because this allows you to check the filters that are around the flyback plus there is more space to work. but I tell you, we have a compressor, so removing it does not take us long, it was a problem before some have as rivets.- so it is at your discretion, basically it is not necessary.
You must have the voltmeter placed at the end of the focus, it will only be an instant. Check the moment you turn on, how much voltage you have. If you had a microwave oven spot you could try too.
Options: 1- check the flyback outside the circuit.- 2.- check the flyback in the circuit, for this you need a vpp probe, I send you a diagram of the one we use. for this it is required: to unlink the b + of the flyback, when b + place a load (the focus) .- to the pin of the b + of the flyback place an external source (15 / 80vcd), place the probe in the hot collector, give it on, and check how much the probe measures.- to know how much to measure, the following is done: the vcd of the external source is multiplied by a thousand, this result is divided by the vcd of the original source (134v) and the latter will be the vpp
example: if you apply a 25vcd voltje to the b + of the flyback pin, and your original source is 134vcd. then (25 x 1000 = 25000 between 134vcd = 186vpp), the latter is what your probe should mark. if you have any source, comment on how much voltage it is and we will make the bill, this operation is called a rule of three) .- The original probe is in electronic community, but we have made adaptations and it has given us results even for switched sources. greetings everyone.
It could be the flyback, if any of the windings were short this would cause the flyback to warm up and the source would be unstable. but the best will be to prove it in working conditions.
Something you can try is the current consumption. just place your ammeter instead of the focus, and it should not exceed 0.500 m. check the cover of the tv, if you have how many watts it is, just divide the watts between the vca and the result will be the consumption of the flyback, it could be less, but never greater. regards
example: if the cover or cover has that it is 70w, then divide the (70 between 120vca = 0.583ma) .- this would be the consumption of the flyback .- comments. regards
1. You will have to check the watts you have written on the cover or cover, because if it was 110watts and the vca is 110, the consumption will be 1 amper, which seems too much to me.- 2.- - not to expose the ammeter the current can be known with the ohms law.- so place a resistance of 4ohms 10w or less but instead of 10w instead of the focus, and in parallel with this, place your voltmeter, check how much voltage you have, divide the voltage Between the resistance and the result will be the current. (I = V / R) .- generally the minimum flyback consumption is 250ma ........
...... Comment when you have armed the probe to explain how to test the flyback. The steps will be numbered to be more located in case we have an error of appreciation. for now we will check the current consumption. Finally it is correct: place the flyback and the hot, the ammeter is placed between the b + of the source and the pin of the b + of the flyback. Regards.
Hello Felipe, the voltage is 220v, thanks for your measurement tip, I will see if I get the flyback, the current consumption measurement I would like to try, we must not put the tester in series between the + by the + b of the flybakc but it does not work I don't know why, as for the probe I would have to get the variable source of how much voltage and how much current the source should deliver, I will build it to have it.
To test the flyback any source is useful between 15vcd to 80vcd.- if you have a digital multimeter there is no problem with the placement of the cables, but if you use an analog multimeter, the cables have to go with the polarity, otherwise the needle moves to the opposite side. Now if the watts of the TV are 110w between 220VAC the result is 0.500mA up to 0.600 would be acceptable.- greetings
Comment on current consumption. Either with the resistance of 4 ohms 10w or less, or placing your ammeter in series with the line of b +, you will have to arm the probe to measure the vpp in the collector. Comment if you have any source that you can use as an auxiliary source.
You have to do the test with the resistance, to know the consumption current.- For the source it does not have to be variable any voltage between 15 to 80vcd is useful to you. of the probe that sends you the diagram you can change the three capacitors by 0.1 uf 600v) but the source must not be greater than 50vcd.
5w resistance is useful to you, just comment on how many ohms it is? .- On the other hand it is correct, the voltmeter is placed in parallel with the resistance, you must be careful because it will not be much what it indicates, that value in volts you divide it Enter the resistance value and it will be the current consumed by the flyback. Just check that the resistance is of the indicated value, since some are 4 ohms and have up to 8 ohms. It is good to ask any questions.
It serves perfectly, just make sure it is 26vcd.- because if you multiply 26vcd per thousand between 134vcd the result will be 194vpp.- this is what your probe has to measure when you place it in the hot collector. don't forget that you have to place a load on the original source (the focus).
Maestro Miguel.- Nice to greet you. I said something strange. - At the beginning I was sure that you had commented, but when I looked for your comment I did not find it, I even thought it was confusing. . we are in the matter of the probe to measure the vpp in the collector. Best regards.
You can use 1n 4936 diodes, but the maximum voltage of the auxiliary source should only be 50vcd.
It is a very rough diode, it is better the secondary diodes of the flyback, if you had any plaque, from there you could get them.
If the auxiliary source is 26vcd and the original source is 134 vcd, the vpp in the collector will be 194vpp - as for the diodes you have, I don't know how much capacity they are. but if they support a minimum of one amper and drive 600 or a thousand volts, it will help.
Those diodes will serve you. Remember to check the flyback consumption with the resistance first. then check the vpp in the hot, write down each step to follow a sequence.
The consumption of 0.303 m is within normal range. ---- The probe: 1 .- the focus goes from b + of the original source to ground. --- 2.- the external source goes to the ground and the positive goes to the b + pin of the flybak, --- 3- the probe goes to the hot collector.- you have to connect both the TV and the source external.- 4.- the multimeter is placed on the vcd scale.- check the probe assembly well. A test that you can perform, place the tips in the VCA socket and comment how much it measures .......
when you connect the probe to your VCA line (220 VAC) .- the (Vpp = VCA x 1.41 x 2) .- Example: (220 x 1.41 = 310 x 2 = 620 Vpp) .- Check the probe connections well , the multimeter is placed to measure vcd. note that if the watts are 110w, and the voltage is 220 the current would be 0.500, in these conditions check the filters, because you do not have an over consumption, what you can have is; As indicated by Miguel teacher, a filtering problem. For this you need an ESR meter. greetings everyone.
If possible, upload a photo of the probe so we can see the assembly and condensers. in the probe, earth is chassis ground, input is where you are going to measure, the red dot is the positive of the multimeter, and the black is the negative of the multimeter. Note that the multimeter negative is not the ground negative.
If I test the positive of the tester between the negative of the diode and the capacitor to ground and the negative to the positive of the other diode and the other earth capacitor I put it like that and it marks me 1.5 the tester, felipe the rs3fs diode is a damper or a fast diode the data tells me a quick rectifier but looking for a damper as a replacement you are in the hot collector.
Philip this is the diagram in case you want to see https://drive.google.com/open?id=1f_Mr0jWNMv9L2Fw1xXF5BpeALh6TUGjr.
I cannot see the diagram, mark error 404.- Of the diodes they have an anode and cathode.- the positive of the multimeter is connected to the cathode of a diode, and the negative of the multimeter is connected to the anode of the other diode. the capacitors are 0.1 (100 nanos). Send a picture to see the connections.
Sorry felipe https://drive.google.com/open?id=1f_Mr0jWNMv9L2Fw1xXF5BpeALh6TUGjr the end point is not going to know that change the diode rs3fs for a ru4ds that is a damper and burn it along with it with a 4.7 50v unpolarized condenser.
The diagram could already be downloaded. Now send the photo of the probe to analyze the connections and the type of multimeter you have.
If you look at the probe diagram it has indicated: multimeter in vcd.- Now we can measure the vpp of the hot.- be careful. and comment how much the probe marks.
It is a low voltage.- because you should have 180 / 194vpp.- note that the flyback current consumption is also low, because it should consume 0.500 m.- and you only have 0.303 m.- you need to check the filters, both those of the source like the ones in the flyback side. In the late night today we analyze the diagram and later I will tell you. Regards.
It's good that you have an ESR meter - all the filters we measure have to be less than 5 ohms, with the exception of the 1 to 160 filter that measures 20 ohms - so the filter you have of 10 uf / 250v and that Measure 20 ohms, you must change it. You can measure another and compare. But in fact it is wrong. even the resistance of 3. ohms you have, you put it and check how much it measures, and all the filters should be in that measure or less.
Try to measure 3/5 filters of the same size, so you will have a table of values and it will serve as a reference. The 4.7uf to 160v filter is also too much. adjust your meter with a resistance of 3. ohms or 4.7 ohms, and check how far the needle moves, all the measurements you have will be less than that value. but never older. Regards.
It is very common that new are not synonymous with "good" .- Here in Mexico there is also no quality control or ethics of traders .- .- But good that now you have the reference of the resistance of 3. 3 ohms, all have You mark less than that value. It does not matter that the placements recovered from other plates.
Already this felipe I did the tests of return the one of the consumption gave me 1,100 and low to 1,084 it stayed so then it would be 1,084v / 3,3 ohm = 0.328 the strange thing that the TV turned on and before in the previous test it did not turn on, the test of the probe marked me 114.5 it stayed that way there it was not moving what else should I check or try how the TV works now.
With the normal TV, just leave the resistance to check the actual consumption. as for the filter of 10 times that of 4.7, just as proof, since the difference in filtering is too much.
You leave it running normal, you only monitor the resistance voltage. if the source becomes unstable, check if the current increases. Write down the voltage vs. consumption data so you have a reference.
I tell you.- in manuals and contributions there is a folder: color adjustment tv.- download the folder and this contains a pattern of adjustments, it will help you to adjust the focus and screem as well as purity.- you only connect it to the tv, with a dvd and you can check with the probe, the vpp in the cathodes of the kinescope, because it has color patterns. regards
You can remove the color, and when it is black and white adjust the focus and the screen.- Wash the chassis with two parts of thinner and one part of alcohol, this allows you to "see" the state of the welds. Now the beep is from the source or the flyback. check the filters of the vertical section.
Good felipe if there were capacitors of more than 10 ohm in the vertical one of them of the line of the x-ray that I lower it to 2.5v now there is 4.45v, the noise that is now very annoying is missing is near the flyback this is Because of capacitors, the resistance consumption continues at 1,100 - 1,085 greetings.
You can try lowering the source voltage. at 125vcd.- it is these Czech conditions if the noise is eliminated and also if the screen reduces.- if this occurs, the voltage increases gradually until the screen is filled. Well, 134 VCD seems too much to me.-
If the coils are overheated, change the tuning capacitors, these are the ones that are connected to the hot collector, and even if you can change the yoke, this to do .- because the tracks overheat when the capacitors or the yoke are leaking. Lipia well all that section, if possible remove the flyback so that everything is clean with the thinner and perfectly dry.
I do not have another yoke, but I had already taken it out and cleaned it because there was a lot of dirt on the neck of the tube and because of the humidity the winding of the yoke had been checked with the tester that bob parker for coils that I had done and all the LEDs they turned on, excuse the resistance to measure the consumption I leave it if I'm going to lower the tension of + b will not affect.
You can leave the resistance, it does not affect you, because the voltage drop in it is not significant. Good thing that little by little you are getting your equipment.- A chopper or flyback "pita" when it receives an overvoltage, it lacks voltage, or fails to supply the consumption that is requested. By reducing the input voltage, you can analyze if it is the primary part, or it is the secondary part.- Comment if you downloaded the folder, this is useful, because you can see if the lines have fluctuation. when you place the grid.
If I download the folder then I will do those tests I have to buy the CD but first I want to fix the noise problem is very annoying I hear it near the flyback, these high voltage capacitors there is some way to check them for leaks or failures internal with the capacitometer they mark me well.
The tuning capacitors cannot be checked with the capacitometer because they are high voltage. - Yesterday, one of the technicians told me that the chopper output has a marked 130 v output, but the flyback input has a higher voltage. Regarding the folder, you don't need a cd, just the usb in the dvd input. the source carries a tl 431 and has a control, so it is possible to lower the tension of the flyback
I send you a diagram of a source we use, for you to analyze. This allows us to apply 125vcd or less to the flyback and check if the problem is the source. It is not necessary that you do it now, but it is a good project, a good tool and it is proven.
If I can regulate the voltage with the potentiometer, the D411 diode that is an rs3fs is in the hot collector I replace it with a by228gp is ok and another thing the probe is better byw96 diodes these are different from the fast diodes that I would change the measurement asked why I will make it on a plate with the cables well done greetings.
We have two probes. one with capacitors of 100 nanos, and diodes 1n4007.- this only to check the oscillation and check the flyback as long as the voltage is not greater than 50vcd.- the other probe that carries the diodes byw 96, was made by one of the technicians, I look for the data and it is the one we use for switched sources.- It would be your discretion to look for the datasheet and change it.- much of what I write, is not only my experience, but also the opinion of the technicians when they are here.- we try to help as much as we can. Now we have an oscilloscope, but the probe is more practical.
I send you a diagram of a probe that we use to measure the video signal at the exit of the jungle.- and another probe that is the one that carries the capacitors of 0.1 nanos 600v.- basically the only thing that changes is the value of the components. We have checked these, one is from English, the other the original is in electronic community, but I have not made the adaptations, but I have checked them.
the video probe is only used to check the video output pins of the jungle, the reason is that the 1n4148 diodes only support 50vcd, the other probe can be placed perfectly in the cathodes of the kinescope, heater, check the oscillation in the collector of the driver to the base of the hot, check the flyback but the voltage applied to the fllyback using this probe should not exceed 50vcd. With the other probe that I sent you first we have reached 80vcd.
Lower the voltage of + ba 130v but the noise continues I think that near the horizontal transistor there are three high voltage capacitors I will see if I get them, excuse felipe the jungle video probe which is the formula I should use and for cathodes and the heater is the same collector formula.
If at 130vcd it works without affecting the size of the image you can leave it.- to measure the vpp of the jungle, as well as the signal of the heater and the cathodes of the kinescope, the measurement of the voltage is direct as is the mark of your meter. for the hot collector if the rule of three is used, because the constant has a value already determined in this case d (thousand) -
If I understand that in the collector there is high voltage and high frequency, then for the jungle the cathodes and the heater is direct but my doubt is what values it should have when measuring, and another thing is the effect of changing the channel the image shrinks and then back to normal can be cause of tuning capacitors.
There are diagrams that have their oscillogram marked, when we start using a sanyo diagram as a reference.- example the heater measures 18 / 22vpp.- even now you can measure them, both the heater and the cathode. That is why the pattern of ajste is important, since having a still image allows you to check the cathode in its real value, because in other conditions its value fluctuates.- Finally, I think that the image shrinks due to feeding problem, filtering .
Thanks Felipe, I understood, in the probe with the diodes in4148 it is for the jungle there is an R2 potentiometer as it is necessary to adjust it and the other all the capacitors of the + b I check them with the esr meter and they mark me low values there is something that could cause it primary or secondary chopper transformer and check everything will be checked again.
The 1n4148 diode probe, you only adjust the control to 0.040 mv. once you adjust it you just fix it with silicon and that's it. Remove the flyback and the hot, wash the plate very well and check all the filters.
The flyback primary line has a 22uf 250v filter, and on the kinescope connection card it has other filters, try checking or changing them.
First.- Nothing ignorant.- Here we learn, analyze and execute.- Two ohms is not much, you can even check it with the esr meter, also when you connect it check the 5 volts, the voltage drop in the resistance must be less than 0.5v.- remember that when we talk about a voltage drop of a resistance, it is when the voltmeter is placed in parallel with the resistance.
Good felipe I need to ask you two things the tuning capacitors I must respect their capacity they did not have the same value are three 7200 pf, 6300 pf, 3900 pf all 1600v you can pass the value of their capacity and how much, and cleaning I found the buttons of the keypad With 20 ohm, this can cause errors when giving orders to the micro channel change, turn up volume to turn off greetings.
The flyback, the yoke and the tuning capacitors, all of them are a set and are designed to work at established values. If you change the value it will be reflected in the width.- In addition the cut of the vpp signal of the hot, works with the yoke and the capacitors. If you change the values you can heat the hot.- With respect to the switch of the keypad, they have to mark continuity, you can test them with the meter of esr.- since there are multimeters that "whistle" at 10 ohms and that does not It is a continuity. Regards.
Thanks I just measured with the esr some mark me 15 ohm, I will see if I get the capacitors of the same value to test and another question in the horizontal driver transistor is a c2482 which is with transformer you can make voltage measurements at the base or collector greetings.
What do you mean make tension measurements? .- In the driver transistor you can measure the vcd in the collector, and also in the base, in fact it observes that if you place the voltmeter in the base of the driver and give it on, the voltage is 0.300mv, this in terms of voltage.- You can measure the vpp in the collector by placing the probe, you can also measure the vpp in the base but you have to place the other probe because the vpp in the base is only 1 vpp or 1.3vpp maximum.
I wrote to Master Miguel, telling him about the problem we have in the flyback. I hope with your opinion to solve the noise problem.
Master Miguel I inform you: I don't know what kind of noise it is? , it only talks about a noise, we lower the voltage to the b + (130vcd) and the noise continues.- what I do notice is that the consumption ampmeraje is low (0.300ma) and the vpp in the hot collector is also low .- It seems that the yoke is fine, and the flyback says that I already change it.- it is a pleasure to participate with you. best regards.
What he also comments is that when the channel changes the image is affected, this according to me is a reason for the feeding.- but hopefully now it provides more data of the famous noise.- greetings
The image when changing the channel makes an effect I don't know how to say it gets smaller and becomes normal again, not very exaggerated a bit but I found the pushbuttons with resistance still do not change them after I try the new ones, the varnish I have to get it and the glue of what kind.
connect the probe into the 220vca socket and comment how much it measures.- because we have to 125vcd in the driver transformer the vpp is 150 / 2000vpp.- so 59vpp is little.
Change the filter that is in the driver's collector is the C 401 of 4.7uf 160 volts.- Note that the driver's collector has marked the oscilloscope number 16, comments how much voltage the driver's collector has.
If the 4.7 filter marks well, the transistor changes, checking the voltage in the driver manifold should not affect you. , neither does the probe.
You can even place the probe in the base of the hot, turn on and observe how much it measures, only that the probe has to be connected. I have an ERROR, when giving you the pp value of the Driver's collector, it is (150 to 200 vpp) .- it has written 150 / two thousand) which is an error.- sorry to write the amount incorrectly.
Everything that is overheated in that area of the driver transistor will have to be changed. The voltage in the driver's collector will be at least 70vcd.
The probe that we will be using in the transistor driver, is the one that has the 100nannos capacitors and diodes 1n4007.- the collector has marked the oscilloscope number 16, so placing the voltmeter or the probe does not have to affect it. Check the vpp in the base of the hot must walk for 8vpp.
The probe that we must use is the one with the 1n4007.- check the voltage of the driver transformer at point number two, it is the one that goes to b + (according to diagram) .- at point number one, which is the point that Go to the driver collector can not have 30vcd.
The collector voltage of the Driver, cannot be 30vcd, has to be at least 60 / 80vcd. and the vpp must walk for 150vpp. So change the transistor. and check well until the collector has more than 60vcd. I don't think so, but suspect even the driver transformer.
To measure the voltage drop of a resistor, just place your voltmeter in parallel with the resistance. - Then divide the voltage by the resistance value and you will get the current flowing through the circuit. (I = V / R) .- The transformer driver I think is fine, because the measurement of us is 54 ohms the value of the primary.- what you can measure from the Hot is only at the base and will be with the probe, its value It is about 8vpp more less.
Now I explain the mathematical part of your probe.- at 200VAC multiplied by 1.41 by 2 is equal to 620vpp.- These 620 are 100 percent.- If your probe measured 452 vpp, these multiplied by 100 and divided by 620 vpp is equal to 72 percent.- means that your probe has an effectiveness of 72% .- in the case of taking a measurement of 100vpp your probe will measure 70vpp.- if you measure 200vpp your probe will measure 140 vpp.- that is why it takes a record of values for the probe.
This means that the resistance is fine. note that the resistance is 5w.- if you divide the 5w by the resistance value (4.7 k ohms), you will have the current.- (5w / 4700 = 0.001 you take the square root and the result is 0.032.- So Change the transistor.
Having a smaller vcd, it is an echo that the vpp waveform is smaller too. This causes the flyback, the hot and the yoke, not to work properly. We have been saying that the amperage is not long ago, as well as the first vpp measurements of the hot collector - it is a shame not to have the original oscillograms. That's why references are used.
Write down a sequence of the work on a lilbreta, with data, details and you will have a reference for future work. - So we started, then when they brought the oscilloscope, we had to take a course in applied mathematics to use it. regards
Master Miguel which thinks that it only has 30vcd in the driver's collector, I have a reference of a samsung tv, which at 125vcd the driver's collector should have 73vcd and the vpp is 200, which in this case the probe will measure 140vpp, which neither we have. What do you think?
I will put the driver part, but we only have the oscillogram number, not the oscillogram sheet, nor the collector voltage.
Maestro Miguel.- in the conditions in which it is, the resistance 404 of 4.7 k ohms, dissipates a voltage of 100v. which (subject to what you think is too much) .- any indication? .
If you had a chassis of another TV, or a board of the part of the video amplifiers you could use it. as these transistors feed more than 100vcd and the pp voltage is 100 minimum.
Do the test but remove the hot, place the voltmeter in the driver's collector and check how much it has.
we will have to test the driver transformer. will you have any badge? . In addition to checking each component the condnssadores, the filter. but it is an echo that has to have more voltage. - Here it is already 4 pm. So we will continue tomorrow. greetings everyone.
they will only be useful if the primary receives a b + of 125vcd. By the way, what time and day are you?
I'm in a town, San Jose Iturbide Guanajuato Mexico. Then you have two hours in advance, here it is already 16 hours 10 minutes. best regards everyone.
If possible, get the diagram elsewhere, but have the voltages and the oscillogram sheet. If possible, I will come at night in case you have any news. luck
Tomorrow I'm looking for an oscillator to avoid relying on the jug. and we can check the vpp. del hot .-- - will you have a black and white tv that has an input transformer? .- greetings.
Good morning Felipe, I found two driver transformers with + b of 110v and 130v but when trying to hit on TV one marks me 14v and the other 12v this with the lamp as load I did not find more info only that the tr driver collector must have a 60% of the + bo be 70v as you said I don't know why the voltage drops from 30v to 14v greetings
felipe doing new tests I raise the hot emitter I put the transformer that marked 12v now marks me 62v with the emitter and the collector lifted and with the lamp as load I put the original transformer and now it marks me 57v because this happens just raise the emitter greetings.
Mr. Galaga.- Good afternoon.- It is excellent news, Congratulations for your perseverance and I thank you for allowing me to comment on your post. - remembering that your probe only measures 70% .- The operation is called a rule of three.- (150vpp = 70%) then (100% X 150/70 = 214 vpp) .- You already have a reference to know that in the driver's collector you have 150vpp, for this to be fulfilled, said collector has to have its vcd set. The main thing will be ...........
..... the main thing will be that when doing any test, we do not lose the reference of 150vpp.- You can change the hot, check the ohmiaje or bypass the coil L 412.- As an exercise you can comment how much of vpp you have in the base Of the hot if the measure is 5.7vpp and that is 70% .- I think you have a taste for electronics. - I hope you will allow me to reach the end of your post, and find in the applied mathematics another way to solve.- Best regards.- Felipe Antonio Ascecio
Now that we have 150vpp, and 57vcd in the driver's collector, options: 1.- check the consumption with the resistance of 3.3 ohms 5w, between the b + and the b + pin of the flyback.- 2.- check the vpp in the hot collector, but remembering that you have to reduce the voltage to the b + pin of the flyback. Remember that the constant for the hot is 1000) .- comet. Regards.
Good morning Felipe my name is Pablo thanks for the comments but the grateful one is me, I only do what I decide to the letter as for the hot trasistor I change it and it does the same thing to me I start raising diode capacitors in the emitter line I get to the primary of the transistor driver the capacitors C403 and C402 I lift the pins that go to the driver and I see 160 changes them for new ones the 390pf I did not get one of 470pf but when measuring with the probe it marks 62 greetings.
We will try this way: 1.- connect the bulb between the b + and the b + pin of the flyback.- 2.- The L 402 makes a bridge to the ground. 3.- place the probe in the collector of the Driver, the probe must already be connected. comment how much the probe measures and how much vcd we have in the driver's collector.-
In R 402, it has no voltage drop, (voltmeter in parallel with the resistor) because one end is connected to the power supply but the other end has no reference to ground, when a resistor is placed with a capacitor in series it is only for a decoupling of the alternating signal. The C403 works with the primary of the driver transformer, this capacitor with the inductance of the primary makes the pulse more / less wide.- If we had a partial short at the stage of the driver transformer, it would reflect that we would lose voltage and signal in the primary.
Excuse me, the R 402 will not touch it, it is the L 412.- the one that we are going to make a bridge.- and with the primary of the driver we will not touch it. Sorry for my mistake, sorry.
I send you a photo of a way to test the vpp in the collector, it is from Master Joansoler.- The focus was connected between the b + and the b + pin of the flyback. I have not checked, but for a while I followed his contributions and directions. analyze it and comment.
In the transistor (hot) it is very common that some diagrams indicate it and others mark it as a common transistor.
As you will notice, it is a simpler version and allows you to leave a multimeter already installed in the hot collector. With this probe of Master Joansoler, it also served as a reference that if possible, lower the voltage at the b + input of the flyback and check the vpp in the hot collector.
There are some Masters who have contributions at an engineering level, there are others more practical, I do not tell you names to not offend anyone, (the artists are sensitive) .- little by little you will know them and you can follow them, you learn a lot from these people , some are given grammar and explanation naturally.
With the resistance I don't think it affects, the capacitor will work but in the b + pin the voltage should not be greater than 80vcd, as for the diode it looks for the datasheet and compares. now at 80 vcd on the b + pin they are: (80 x 1000/130 = 615vpp in the dle hot collector.). Check the accounts anyway.
I am going to send you an oscillator from Master Luis B.- I found it here in the Forum. I didn't find the last name, this Master made a flyback tester, we cut the oscillation alone, we have an external oscillator so as not to depend on the jungle. In this oscillator, the regulator I think is connected in that way, by the aesthetics of the diagram. but in reality the connection is reverse.- it is not necessary to do it now, we have one of a black and white TV from 15 years ago.
The source is regulated at 130vcd, and then you put the focus between the b + and the b + pin of the flyback, this will be enough to lower the voltage at the input of the pin. What we are looking for is: knowing if when we have 150vpp in the driver's collector, how much we have of vpp in the hot. Sometimes the tracks are cracked or cracked, check well, because if the oscillation were intermittent the hot can get hot.
In the case of the diodes, they would be in parallel, not in series.- and Master Luis b's flyback tester is in this Forum, in Manuals and Contributions, you are looking for a flyback tester. There is the complete circuit. You commented that you did the ESR tester, so check the connections of the regulator, as for the oscillator, participate with an ing, analyze it and approve it. We have not done it. if you find a bn chassis that has driver transformer and oscillating coil. You can have an external oscillator.
You can use parallel diodes. Look at the oscillator diagram. 7808, the positive input "enters" on the right side, and the regulated output "exits on the left side. when in fact it is the opposite. I suppose I present it this way because of the aesthetics of the diagram.
This oscillator and your 26vcd source, would serve not to depend on the b + of the original source, nor the d oscillation of the jungle.
we have a flyback tester from Ing Orozco. So it was not the tester as such, what we were looking for, we have an external oscillator, but there is no black and white TV anymore, so the oscillating coil is gone. We needed to send a companion an oscillator and I found that of Master Luis B. - It would have been nice to know the last name, but still we recognize and respect the credit.
At 25vcd per thousand between 130son 192vpp) .- as your probe marks 70% .- then 70 by 192 between 100 are 134vpp.- you have 105 is not too much- how much we have of vpp in the Driver's collector, .- the other test that We will place the focus between the b + and the b + pin of the flyback and check the vpp of the Driver's collector. Not from the Hot.
The vpp test in the Driver's collector is placing the focus between the b + and the flyback.
You will have to get a focus of 75 or 100w of the old ones. because I asked a technician and he says that the "saver" bulbs don't work.
Having no focus, the source cannot protect it. you can place the resistance to measure the consumption and in series with the resistance a fuse of 1.5 / 2 amps. and it is correct we will check the voltage and the vpp of the driver.- Note.- tomorrow I have to go to the city and return until night. Basically I will not work tomorrow, but I come at night and I hope we have more good news.
I don't really know - but being a focus and staying in series between the b + and the flyback, nothing serious could happen - you can try one and if you have another you can also try, because they are 30w bulbs, so to have 60 or 90 w you would have to place it in series.
Good afternoon Felipe I was without electricity from 9 in the morning just at 16 I was doing tests with the resistance of 3.3 ohm the power on ignition is 1,140 / 3.3 = 0.345 and then it is at 1.080 / 3.3 = 0.327, with the probe The base of the hot 08.96 in the driver the base 0.750 and in the collector 55.7 and the voltage is 28v, the + B has 127v, the voltage of the + B does not fluctuate, it remains in 127v, the effect that the screen shrinks, I do not notice it , the buttons were wrong, I changed them but the noise starts when the TV works a little while before and it is very annoying greetings.
Felipe I was checking the coil L414 that goes to the yoke of the horizontal has separated the part of the winding where it is supported, that is, it has two parts of the coil and where it is supported otherwise the meter of esr the coil measures 15 ohm you will tell me but the coils will not They should measure high resistance greetings.
Mr. Galaga.- Good evening.- I have reviewed two diagrams as a reference, both in the driver's collector, have a voltage of 60/75 vcd, when the b + is 125vcd. You have a voltage in the collector of the driver of 28vcd, and 55 dpi. work based on an oscillation, it detects when it is a coil.- We measure a yoke and only if the needle moves, only the focus of continuity.- .......
If possible measures a pair of yokes so you have a reference for measurements in ohms, as well as the Meter measurement of ESR .- We have a problem with another computer shop, they can not remove the disc information hard, but tomorrow I will look for a circuit similar to the oscillator, only this signal is injected into the base of your tv.- driver Echo removing the hot, place the load (the focus) should suffice for the tengmos vcd and vpp in the driver collector.
A test that we do when we do not have the filter of 4.7 uf at 160v C 401), is to remove it and we put a 0.1uf to 200v condom. This test is done by removing the hot, to be able to check only the primary part of the driver transformer.- If it were possible to get only an oscillating coil and a 12vcd driver transformer from a black and white TV, to send you the oscillator diagram that we use . of the Czech jungle 5v and 9vcd on pin 17.- greetings.
I send you the oscillator diagram that we use.- Note that the driver transformer only carries one pnta to ground and the other end goes to the base of the hot.
Thanks Felipe if I knew you were staying at night I would have stayed awake and the fault is almost resolved, the diagram is lowered by the coil and the transformer driver of the black and white TV would have to get the electrolytic capacitors and the other capacitors of what voltage They are those of the diagram, and another thing I can use a 48uH coil, this measures me 200 ohm with the meter is a 29-inch TV I can use it as a replacement greetings.
Felipe I was making measurements on pin 9, 5.24 and pin 17 8.77v there is a resistance the R244 at the input there is 9v at output 8.77v, looking for info I found that the horizontal driver collector has 15.7 kHz my tester measures frequencies up to Measuring 30Mhz marks me 15.67 Khz in the greetings collector.
Mr. Galaga.- When it arrived it was already 12.30 pm from your locality.- To your questions.- 1.- all the capacitors are at 100v. and the filters are at 25v.- 2.- you can use the coil, to test.- 3.- if the vpp of the driver collector "falls" it is due to problems in the secondary of the transformer, (yoke, coil, ondenser, some component that gets hot) .. 4.- try to locate the connection, have a good contact and weld it well and then place the varnish.- 5.- according to manuals the oscillation is 15734 cycles, but the multimeters vary by quality of the components ........
....... and brand of the instrument, basically from 15.6 to 15.7 there is no difference to think that the oscillation is the problem.- I tell you: it is possible to get the horizontal signal from the other TV, but you have to have An insulating transformer. You can assemble two transformers of those that use audio equipment (those large) by connecting the primary to the current and the secondary to the secondary, then the output end will be a primary, comment if you have, if you like I make a diagram .-
no felipe of those I have no apology so the horizontal driver is not working as it should already probe with two different transformers and does not change the measures in fact I lower them, I would have to change a new transistor and capacitor only use used, the insulator diagram put it I download it to the pc when I get the transformers I do it would serve as protection.
The voltage is normal because it is a simple source, the tl431 resistors and control, which are part of the sensing, determine the output voltage, if by moving the control we have an effect on the voltage we can determine that the source works.- Comment if you have the possibility of having the transformers on hand.- some TV that we could "get" the signal. - You can place another yoke and try, but you have to reduce the voltage of the b + to the flyback pin, this to check how much vpp has the collector dle hot, with one or another yoke. to discard
Test.- Remove the hot and place the probe in the collector of the driver and check how much you have of vpp, then place the probe at the output of the secondary of the driver transformer, and check how much you have of vpp.- If these measurements are correct, we have A problem in the final part. Something practical: in the secondary of the driver transformer, one tip goes to ground and at the other end you place a diode 1n4148 (crystal) and a 10uf / 16v filter), with this connection Czech if the driver collector voltage drops. All this without the hot. - Any questions, comments.- greetings
you are correct, it is because of the coil, but how much you have of vpp in the driver's collector, this is the reference along with the vpp of the hot base.- if the vpp in the driver's collector falls, then it is not Coil the problem we have of lack of vpp. We already know that the source is fine, so we will look for a component that causes us to lose the signal, and tenson fall in the driver manifold.
I am going to send you a diagram, with the placement of the diode, filter and LED components, to check the vpp of the driver's collector. You analyze it and comment. It will not be aesthetic but I hope it works for you.- we have an oscilloscope, this is a contribution of one of the technicians and even comments that this is on the net. if we do not lose the vpp in the driver's collector, the problem will be the exit stage.
It is correct, without the hot and with the lamp as a load. the measurement will only be an instant, but note that we should not lose the driver's collector vpp. What we are looking for is to check the driver stage.- if the drivr is ok we will need an external oscillator.
The technician says that not all LEDs turn on- With these values we can (except your best opinion) conclude that we definitely have a problem at the start stage. then if we need an external oscillator to not depend on the jungle and you can work the flyback at different voltages.
Then the best opinion will be that of both. One of the technicians sent it to me. It is of the electronics and service of ing orozco.- I have not checked it, but you will have to arm that of the master Luis b.- look for an oscillating coil and driver transformer, or assemble this. but you need an external oscillator. you don't need all the bn tv, just the chassis and from there we can cut the oscillator section.
You cannot place a filter that has polarity, instead of a filter that is not polarized. It is because the unpolarized eliminates a certain part of the wave, either positive or negative, and serves as a reference signal; instead, the polarized ones only work on the positive side of the wave.
The emitter of the driver is ground, and the filter is only decoupled. It is the reference to ground, the C 414 and the coil L 413, are a single unit.
It does not affect, or at least not to cause to have the flyback noises and that we lose the driver's collector voltage. affects the C 421, c442, C 443, these you must measure it with the esr meter, adjust the zero, place the resistance of 3.3 and must measure less than that value.
Whatever component you want to test, just leave the probe in the driver's collector and the vpp should not be less than 100vpp. just as reference.
It is normal for you to have 4vcd, because it only works when there is a hot and yoke signal.
The voltage will always be proportional to what the consumption is - in that area only if the transistors or the mosfet were short, it would cause a drastic voltage drop. When you test the flyback at 50 / 80vcd, with an external oscillator, capacitors in poor condition can be located as the temperature change is noticed.
A test that can be done is: 1.- you remove the flyback. 2- Only connect the b + of the flyback to your external source, the collector, the ground and the abl to ground. - you place the probe in the hot collector. and check how much you have of vpp.- this you can do with the old flyback, the new one, even with another flyback.- the size of the vpp should not vary. Remember that the source always has to have a load.
No! .- The collector has a comma, but it was (semicolon;). Check the vpp of the hot collector and the vpp of the driver collector.
I have not checked either of them, but I think it is better that of teacher Luis b. because in that of ing orozco, you have to adjust the output vpp. on the other hand, that of master luis b, is already adjusted, only to connect to the flyback pin. That of ing orozco, it is simpler there are technicians in the network who speak well of the oscillator already working. do it and in the first opportunity you do the other. and if you got the coil it would be better for us. It is an oscillator that we have checked.
on the other hand if you need a tester, comment and if we have it I send you the diagram. although there is a lot of everything on the network, but then there is so much that you don't even know what to choose.
I send you an oscillator diagram, according to the technicians have already tried it.- it is from a magazine in Brazil. I found it in another forum. This seems better because it has a transformer driver.
If you have 112vpp in the hot collector, and you are using your 26v source, you should have about 140vpp.- in addition there will be no light on the screen, because in the test the flyback is out of the circuit. 130del b + of the original source is equal to one thousand vpp: then 26vcd is equal to 200vpp, 70% of 200 vpp is 140vpp.- for 112vpp you have the difference is too much. test the flyback outside the circuit, both the vpp and the consumption.
The capacitors that are in the hot collector, with the only thing that can be checked is with an external source of 50 / 80vcd.- The flyback test.- 1 you remove the fllyback, 2 .- the b + of the flyback you connect your source external (26vcd) .- 3 .- the hot collector pin you connect it to the hot collector.- 4.- the flyback ground pin and the abl pin connect them both to the chassis ground.- here you go to Write down the consumption (the R 3.3 ohms). the vpp in the hot collector; and the vpp in the driver collector. You can check the new, used or whatever you have.
If possible connect another flyback, to check the vpp of the hot collector. This low should have 134vpp.- 134 is 70% of 192. (25vcd per thousand among 130 are 192vpp).
Mr. Galaga.- we will definitely have to eliminate the driver transformer and place an external oscillator. Comment which one seems more viable. - We use wizard to make some designs. - We have reviewed the two diagrams and the conclusion is that we need the oscillator to not depend on the jungle or the driver transformer, to check and compare the vpp of the hot. regards
Felipe good morning of what size are the images to send I want to show you I have a sharp 1980 the driver transformer the primary brand 100 ohm, the coil has three points but in two it marks me 50 ohm but in the third with respect to the others Two nothing I do not know if it works I do not know how it works, yesterday I tested changing capacitors, driver transformers, driver transistors and I don't change anything I will have to do the oscillator, greetings.
Mr. Galaga.- To send the photo: 1.- you take the photo and keep it on the computer in images.- .- you give it where the pencil is, you look for a small picture where a landscape is, select file, mark the photo and you give it open, send to the server, accept, send ...... and voila.- I tell you: I live in a town.- and in these remote places you still find black and white TV or workshops where they have TV chassis what they call discontinued.- if you live in the city, you may be able to look for some of these places and look for a workshop that has what you need. ........
..... with an oscillating coil and a driver transformer is all that is required.- Tomorrow they will bring a TV, and I will be able to check the vpp in the driver's collector, in the hot collector and I will tell you if this voltage changes. best regards.
Good evening, put aside the TV while getting what is necessary for the external oscillator and towards other things the question is whether I can continue commenting or should I open another question I would like to continue with the topic to ask Felipe how to use the external oscillator, I apologize if I do something wrong by asking.
Mr. Galaga. b nights.- we can if nobody has objection to continue in this post, if any teacher suggests that there will be another, because it does and anyway we continue.-question: which of all the options as to oscillator did ,. It is a pleasure to greet you again.
Thank you Felipe for answering I made the one of the scheme of Luis b I fed it with 12v I measured the output between collector and earth with the frequency mark me 15.50 khz and also I got a new transistor and capacitor for the driver part and I got 28v at 31v, you saw that the vertical that I put on went off well I don't know if it came failed or that but protected now I bought another one and the + b stays at 130v and does not turn off but I continue with the horizontal one is working badly I will look A hot best quality, regards.
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