chassis mc-83c .... 14 in .... I have all the standby voltages + B = 112V, the others according to the diagram .... when giving power try to turn on, the voltages of the flyback appear, remove the HoT and remain the same, change the power transistors and nothing .... what I feel strange is that SW pin of the 12v regulator arrive 13v .... I already changed it and it remains the same ... this pin should arrive 5V ??? Oh, it's fine
⚡ Descuentos en cursos en video - Lleva tu aprendizaje técnico al siguiente nivel y aprovecha precios especiales antes de que termine la oferta.
🔥 Aprovechar oferta ahora 🔥
Tube TVs
chassis mc-83c .... 14 in .... I have all the standby voltages + B = 112V, the others according to the diagram .... when giving power try to turn on, the voltages of the flyback appear, remove the HoT and remain the same, change the power transistors and nothing .... what I feel strange is that SW pin of the 12v regulator arrive 13v .... I already changed it and it remains the same ... this pin should arrive 5V ??? Oh, it's fine
Tv lg CP-14B86 does not turn on
27
hace 5 años
hace 5 años
chassis mc-83c .... 14 in .... I have all the standby voltages + B = 112V, the others according to the diagram .... when giving power try to turn on, the voltages of the flyback appear, remove the HoT and remain the same, change the power transistors and nothing .... what I feel strange is that SW pin of the 12v regulator arrive 13v .... I already changed it and it remains the same ... this pin should arrive 5V ??? Oh, it's fine
30.814
hace 5 años
hace 5 años
Hello Friend. In addition to checking the q16. check the vertical stage it may be that the ic.vertical is failed and its filters that are related to it are dry, and solves all the cold welds you see on the plate, and solves the choper and flayback pins, and checks the tsh It may be short. regards
27
hace 5 años
I have the la7840 desoldado and does the same thing ..... try to turn on .... I will do the tests
27
hace 5 años
I simulate the ignition by injecting 5v and the flyback gives its stable voltages .....
27
hace 5 años
Friends ... investigating more I did the following test ...... the Q13 (C945) desolder the collector pin (pin2) which is what the SW for the 12V regulator does through a resistor and the TV turns on just I connect it to the AC network but then it does not respond to the shutdown order ..... I just connect the pin2 the TV turns off and presents the fault that you want to start .... any suggestions
46.781
hace 5 años
hace 5 años
Diagram here:
http://13-norte.blogspot.com/2009/03/lg-chasis-mc83c.html?m=1
Place a light bulb (70w / 100w) in series between + B and the FBT.
Comment on what effects you see in the focus on both STAND BY and the ON order
27
hace 5 años
I connected a spotlight and standby does not notice that it illuminates and when giving power opaque illuminates .... it runs 260mA .... suggestions
46.781
hace 5 años
In STAND BY the focus must be completely off.
If so, with the test we are corroborating that there is horizontal oscillation.
Take a reading on the RESET pin of the micro processor and indicate the reading you get at that point, both STBY and ON.
The problem can also be caused by the EEPROM. Try another one, previously recorded with the DATA or brand and model information.
27
hace 5 años
In the reset pin of IC01 in stby = 4.99V and when giving pwr = 4.99V ... it does not change ...
46.781
hace 5 años
How are your advances? ?
After all the tests he has done ....
What is the current state of the tv?
17.741
hace 5 años
hace 5 años
It is logical that you do not react when giving PW because you desoldo the Q13. That way he is forcing the source to boot. Reason that does not obey when giving PW.
I don't know how it measures or where that 260mA voltage. If it says that the light turns on and dim. That voltage does not turn on a common LED. But you turn on a 70w or 100w bulb. That is very rare. I put 200w focus on SERIES. Everyone has their way of working.
You should measure the tension at both ends of the bulb in this case. Apparently short has not. But you say ST doesn't turn on. That means you have Q13 in place.
In focus should be common. Incandecent filament. No other.
The test results in the horizontal oscillating. Measure tension on the tube plate and comment. See if filament is on. I would increase the power of the focus. 200w
place the focus as shown in the figure.
see this photo where you show the R
you say they don't carry.
see this photo where you show the R
you say they don't carry.
27
hace 5 años
Hello friend Luis ... I put the incandecent focus again but of 60w ..... in stby the focus does not turn on, when giving pwr the voltje in the focus reaches almost 42V and immediately returns to zero ..... In the tube plate I have all the voltages ..... when I remove the Q13 the TV turns on just as soon as I connect it to the AC, but it does not respond to the power button ...
17.741
hace 5 años
I already told you above that it is normal not to respond when giving PW or wanting to turn it off. Because the Q13 receives the start and shutdown pulse of the microphone. If it is not the source it delivers all the correct tensions. If there is no other problem.
You should focus without placing the Q13. For the moment .
If you place the focus in parallel between the + by mass for a long time, does the source voltage keep stable and what is its value?
27
hace 5 años
I repeat my friend ..... when I remove the q13 the TV turns on directly and gives an image ....... when I put it on doi pwr and tries to turn it on but off immediately .... change the q13 ... I brought a c945 and I changed it and it remains the same ..... according to the diagram it says c3198 I put it on and it doesn't turn on ...
27
hace 5 años
I ask if I remove the q13 I can let it go straight on or I just connect it to the AC ... or it is necessary to put the Q13 .... I put a switch on the AC to turn it off ..... or open a problem if you work without that Q13
17.741
hace 5 años
Remember that you have the focus on SERIES in + b. It is limiting. I submit it to the source alone with more load first. Without Q13 If it responds well I just give it an ok. If you look at the cover of the TV you will see its consumption. Tell me that.
17.741
hace 5 años
The focus in series is to protect something from breaking. You should take TSH temperature and see if it does not heat the flyback. I already told you that I put focus of 200w in series. And I control everything. Tensions that many times will be reduced by the focus. Some tv does not turn on filament but they are walking. At least flyback temperature and TSH are taken. Even the image often shrinks both vertically and gorizontal by the focus. It is normal. If you can but it is not advisable what you want to do. Removing the q13 and setting a switch. If the tv is being protected. And doing that you are
17.741
hace 5 años
You are forcing me to walk. It must be a small thing. Be patient and it will come out.
27
hace 5 años
Ok friend, I went to get the 100w bulbs .... it doesn't have the ticket ..... it's a tv CP-14B86
17.741
hace 5 años
It's okay. Do this. Remove the focus and place directly now. So before you put it in series with the + by the flyback. Now connect the flyback pin.
27
hace 5 años
I put a focus of 100w in series .... in STBY + B = 112V focus off .... when turning ON + B it falls down to 87V and the focus turns low under ....
17.741
hace 5 años
Friend, did you change the filter of source C 825 and 2 of + b C 814 and C 829 ?.
17.741
hace 5 años
I put a focus of 100w in series .... in STBY + B = 112V focus off .... when turning ON + B it drops to 87V and the focus turns low under ....----
------------------------
This confuses me again.
What tension do you have in filter C 816.
That focus you have to put in parallel so force more work to the source. And if it gives you the 112v that in the diagram says 115v. The source is fine.
27
hace 5 años
I already put it in parallel and it gives 102v in + B ... that 100w focus is not much load for a 14 inch TV
27
hace 5 años
But it doesn't stay on ... I mean, when you press PWR it goes up to 111.6V but immediate faith goes down to 102v ... that is, it does not stay on ...
Think will be the source?
17.741
hace 5 años
It seems that I do not understand myself friend. How are you going to give PW if I'm telling you not to put or disconnect the Q13. So the source starts up alone.
17.741
hace 5 años
From this result draw your conclusions if the focus of 100w is a lot or not.
102V in stby and 111.6 in ON
That tv should consume 75w or more when working and with an antenna attached.
27
hace 5 años
Ok ...... I already removed Q13 and put wl 100w focus in parallel entrw wl + B and gnd ... and gives 111.2v
27
hace 5 años
Place the focus of 100w in series at + B "WITHOUT THE Q13" and the + B is at 87V ...... focus is half the brightness that gives ..... dimly high I explain..q more I make
27
hace 5 años
With the serial focus the voltages in the katods were reduced to 130v each ... and I don't see what turns the filaments on
17.741
hace 5 años
If you have 87v on the + b pin of the flyback with the focus in series and removed Q13 you have a lot of consumption. something is wrong. Remove the plate from the tube and measure again.
17.741
hace 5 años
I was reading above and you say you have 87b of + b with the focus of 100w. So what you say is not correct. You can never have 87v also on the flyback + b pin.
17.741
hace 5 años
Do not.
Something else notice from pin 8 of micro IC01. Exit R 57 and go in series with R 49 and in the measurement of these makes a derivation look where it goes. What component. And comment.
27
hace 5 años
The test I did .... I put the 100w series focus on the + B line, where the L802 goes, remove the connected Q13 and measure the voltage at C814 = 112.4V and at C829 = 108.8V. ... in the pin of + B = 108.8v .... the focus does not come on that I see .... this test the akbo to do ... forget about it before ...
27
hace 5 años
I noticed ... and it does not bring R57 or R49 .... it brings is R35 that goes from pin 8 to where R49 ends ... the derivation of the medium that you mention brings it but it is disabled since it does not bring R57 R49
27
hace 5 años
I repeat without the Q13 and with the focus the TV illuminates the blue screen without the OSD on the screen ..... when I press any button the normal screen appears with rain but it turns blue again ... will it be because of the focus?
27
hace 5 años
Friend Luis ... it's not a blue screen ... it was that the scrin was very high ... I lowered it and the black screen came out ........ I go back and press any button and the raster appears video but it turns black again, I go back and press any button and the video raster appears and it is removed ....
17.741
hace 5 años
What you describe is new. You used to say that TV was good. We will see if this is the case or not. Take out the 100w bulb and place the 60w bulb. With this you reported that he was walking.
Another thing . If the bulb does not turn on you should have the same tension at the 2 ends of it.
27
hace 5 años
Already placed the 60w ..... and does the same focus or turn on .... on one end 112v and on the other 108v .... the screen does the same ... black and I press a button and it comes out the video raster and goes back to black
27
hace 5 años
Ok friend .... it's my mistake .... the FR402 doesn't bring it .... it brings is a jumper ... I removed it and put the focus in 100w series .... + B pin voltage on flybak 87.8V and on the other pin of the 112V light bulb ... turn on the light bulb .....
27
hace 5 años
Removing the plate from the tube, the measurements are 90v on the flybk pin and 112V on the other side of the bulb
27
hace 5 años
Friend, I think it will be the flyback ?????? ... I opened the line of the 180V and 26v of the fly and yet it does not rise from 87V on the flyb pin
27
hace 5 años
But because now the screen turns on and goes black and when you press the polisher, the video raster appears and disappears
17.741
hace 5 años
You have something wrong motive that you measure 87v. It is much consuming. You must have about 1/3 of the voltage of + b. About 40v or so.
The strangest thing is that you don't say anything about how the template looks. With that tension should be reduced. Both vertical and horizontal.
27
hace 5 años
She doesn't let me see her ... if the raster appears in a matter of a second ... it quickly turns black
17.741
hace 5 años
Cut either of the two wires from the yoke of the vertical coil and plug in the TV. And see what happens. Comment If it remains the same, cut the red wire and try. We will see by discard if the problem is flyback or yoke. And another component of the horizontal circuit.
17.741
hace 5 años
When cutting the cable from the vertical should manifest the horizontal. If you cut the red wire and connect the previously voted wire, you will get a vertical line.
If it keeps turning off reduce the scrin and test. Discuss each of the results, always with the focus in series. Measuring ka tension envel flyback pin at home test.
17.741
hace 5 años
I told you one at a time not the 2 coils. Is the plate removed from the tube? Did you reduce the scrin?
Now I tell you well the TSH collector that does not print and put the jumper or coil you took from the + b to the flybac. So this direct the + b to the flyback. And you put the focus of 100w to ground and on the flyback pin that goes to the TSH collector. If you don't understand, you tell me.
27
hace 5 años
I thank you for your great help .... I'll be back tomorrow and I'll take it back ... Tomorrow I do the test friend ... I'm already at my house ... thanks ... I'm taking notes ...
27
hace 5 años
Let's see if I understood you ....... to release the HOT C, put the 100w focus between mass and the + B pin of the fly, place the jumper that was previously removed ..... then when doing this test I must have disconnected the tube plate ?? .... lower the scrim to the minimum ??? ..... that is what you want to do true ...... write down the result ddl tv
27
hace 5 años
I already did the test .... lift the HOT collector, lower the scrin, remove the card from the tube and put the focus of 100w between pin d + B and GND ..... this without the Q13 and the result is + B of 112V ..... q indicates that ..... also perform the test with the Q13 put and the result was 102v in STBY and when giving power 112V but it returns to 102v again bone that STBY returns ... .q indicates this test ???
17.741
hace 5 años
You do not understand me.
1-When connecting the Q13 the source will protect again. The test is WITHOUT THE SAME. 2- The focus is NOT on the + b. It goes on the flyback pin that goes to the TSH collector. .3 - it makes no sense to remove the plate from the tube in this test since the horizontal circuit does not work.
Nor reducing the scrin. The latter were previous tests. That you removed the file. And not as directed. First cutting the vertical winding cable. Then place it as it was and cutting red wire.
The test with the focus on the flyback pin that goes to the TSH collector and mass is to see if it is
17.741
hace 5 años
If it is the flyback in poor condition and another component of the horizontal circuit. It is not 100% sure anything. I mean flyback. It can be shorted when working. The same is the TSH. Or another component.
Read well and take the test. In it the focus should turn on and if you measure the voltage should be + b 112v.
27
hace 5 años
I already put the focus on the collector and the collector measures 110.7v ...... all this without the Q13 .... excuse me for not understanding well ... I am learning ...
27
hace 5 años
I already placed another D2499 and it does the same .... on one pin of the spotlight there is 112v and on the other 88v ..... the spotlight is in series where the jumper was going ...... I think it's the flybac .....
17.741
hace 5 años
Okay. Remove the flyback. Unload the tube before. And it measures on a scale of 200 megabytes in the tester. From the pacifier and the flyback pins. It must not have any continuity. The same between primary and secondary. In primary winding are 3pins. The one of + b, the one that goes to the collector of the TSH and the other pin is the one that corresponds to the 180v. Those 3 pins must have continuity nothing more. If you have continuity a pin of these with someone else. The flyback is wrong.
17.741
hace 5 años
Apobecha that the flyback is not placed and measures all the diodes that are at its outputs. For the vertical. The 180v. Also on a scale of 200 megabytes. In one sense you should mark 1 in the other nothing. Check if the 180v electrolytic is not short.
27
hace 5 años
Hello friend Luis .... I tell you that I put the flyback on another lg tv and the TV is working normal .... which indicates that the problem is on the card .... I already talked to the owner and I agree that change it .... thanks for your help ....
Reparaciones similares solucionadas
¡Aprende a reparar con estos cursos YoReparo!
¿Tienes una mejor respuesta a este tema? ¿Quieres hacerle una pregunta a nuestra comunidad y sus expertos?
Regístrate gratis
Ad