LG TV model 21FX4R ON and OFF
Goodnight friend
Thank you for your help and the plan I comment the following
Make the change for a resistance of 2.7 ohms and nothing is what you said to change the fr402
The voltage at C803 is 180V, the source is fine because the standby LED remains ON
After the chopper in D826 B + is at 106.2V
D823 9.4V
D824 13.4V
IC 804 IN 9.4V in OUT nothing but when turning on the TV in those seconds that turns on it out in 8.8V
IC803 IN 7.1V OUT 5V but only at times of turning on the TV
IS SAYING THE FLY BACK?
THANK YOU
Good evening colleagues
Reviewing topics from other forums on the same problem, I found one of a friend who recommended turning on the TV and without letting it turn off shutting down CH + or CH- and if the TV supports the image by passing channels without shutting down which is Jungle IC501 in my case it's LG631 9R the truth I'm going to try to get it to see if it's the damage
TV-LG-21FX4R chassis MC-059a.pdf [3.67MB]
Good luck friend and greetings from Valledupar, Colombia.
friend expand the pdf file to 300 or 400% so that you understand well the points that I indicate to you.
Good evening Mr. Quintero I greet you from Cucuta
I appreciate your advice and the plan
I commented that I got the resistance of FR403 from 1ohm to 1W and change the capacitor C826 and nothing stays the same
THE STRANGE IS WHAT I TOLD HIM THAT OBTAINING CHANGE OF CHANNELS PRESSED AND PASSED CHANNELS WITHOUT AUDIO AND JUST STOP OBJECTING THE CONTROL IS OFF
FRIEND THE IC 804 OSEA THE 9v REGULATOR 9.4V ENTER THE TV IN STAND BY AND DO NOT TAKE ANYTHING ONLY 0.7V ....... WHEN GIVING ON THE TV EXIT 13V AND FALLS AT 8.8V AFTER THE TV IS OFF . AND IT FALLS AGAIN AT 0.7V
GIVES ME THE PRINT THAT IS THAT REGULATOR? TOMORROW I TRY TO GET IT AND I TELL YOU
THANK YOU
Hello friend I hope you are very well, I made some recommendations regarding the 9 volt regulator and the associated filters, followed them ??? I asked him to bypass the regulator on pins 1 and 2 to see if the TV was on, did he do it ???
I suggest you consider the recommendations and comment on them, these recommendations are in the diagram you provide.
Greetings from Valledupar Colombia.
With respect to the 9V regulator, when the ignition order is given, the power on voltage reaches pin 4 and on pin 2 9V must appear and be maintained, pin 1 must increase between 11 and 13V.
if the voltage of pin 4 disappears, the voltage of pin 2 is cut off.
I asked you to bypass the regulator to see if the TV stays on and you can determine where the fault may be, the initiative to change the regulator is good because if on pin 2 there is 13V it is possible that this is bad
lucky friend and comment
disconnect a pin from R421 R407 R306 D404 or if you prefer to disconnect two pins of Q16, leave them disconnected and turn on the TV to see if it is a problem of any of these protections, I have sometimes found Q16 damaged.
In the diagram I leave other recommendations, follow them and when you have made all the comments, I also tell you that if there is no solution with the recommendations I have left then try another fly-back because the one that is installed may be bad.
Greetings from Valledupar Colombia.
between pin 25 "ABNORMAL" and a circuit that has 5V, place a 4.7K resistor to deceive the protection since sometimes the function provided by this integrated is damaged
Good morning friend, I thank you, thank God and you that was the problem
I disconnected two pins to Q16 and the TV already turns on normally with good image and audio.
Only a few stripes appear at the top of the image.
I MAKE IT RARE BECAUSE Q16 AND Q301 WHICH I BELIEVE DO THE SAME WORK DO NOT HAVE ANYTHING.
Now I leave it like that? Or should we get the transistor?
Are those stripes on the top like filters?
Thank you
Hi friend, I'm glad you have a breakthrough in this repair, change C309 and C307 then connect the two pins of Q16.
The filters must be new, with this the TV must start well if it is not being protected due to another circuit.
Comment results.
Regards.
Good afternoon friend
However, I told him to change the regulator IC804 for a new one because he suspected it and re-welded the Q16 and nothing went out again.
I disconnected Q16 again and it works fine.
It will be that I leave it like this ... It only works by removing Q16
Thank you
Ideally, let the TV protection work, in the diagram I recommended disconnecting four pins, now I ask you to connect everything but let's do it quickly to get out of this repair, followed:
1- disconnect a pin from R421 and R407 turn on the tv that happens ???
2- disconnect a pin from R306 turn on the tv that happens ???
3-disconnect a pin from D404 turn on the tv that happens ??? comment .....
If doing all this does not improve the fault, change Q16 and if it does not work, it is a problem of the micro jungle and the solution would be to disconnect to Q16 or add the resistance in pin 25 and where there is 5V to deceive the protection as recommended in the diagram.
Once again I tell you that the ideal would be to let the protection of the TV work, but if it does not work then it would be to leave it without the protection and the TV would work perfectly.
comment
In the diagram, OCP circuit I leave another recommendation, if I download the diagram I expanded to 300% so that you understand me.
I wait for your comment, at the end of this repair I think I have a good score and close the question with an accepted solution.
In any case friend Alonso I congratulate you for your technical achievements.
Greetings from Valledupar Colombia.
Good morning friend the same blessings
Following the plan takes me to FR403 to change it for a new one from 1ohm to 1W. this in turn connects with the voltage + B and through R405 and R406 with the horizontal stage transistor driver the HOT ETC ETC transformer ...
It will start testing everything but everything looks good
I will continue testing and let you know
Thank you
amen, good morning friend Alonso, read what I wrote in the previous message ??? Because I have the impression that no, I told him where there is a recommendation and what needs to be done.
check the status of Q403 change C407_C409 and C835
FR403 = 1.2Ω 1W if the one that was set measures that impedance "1.2Ω" put it, if FR402 is set it must be in good condition.
If R833 = 0.47Ω 2W should be fine.
Good friend to give you, good day.
Good Morning
Friend what a shame but I dedicate myself to the air conditioners and washing machines for that reason the delay.
Check that circuit Q403 is ok
Change C407 C409 and C835
R833 does not exist there is a jumper bridge
R423 according to plane is 12K this tv is 3K all those resistors R421 R407 R408 R409 and R420 are ok
Connect R421 and R407 and the same problem
I already think about leaving it that way without connecting those resistors
Thank you
Ok, don't forget to rate my contribution and see the question as an accepted solution.
LOVE friend Alonso, GOD gives you many blessings, including wisdom.
Greetings from Valledupar Colombia.
Good afternoon, I loved it
Post on another tv with problems like this:
Good afternoon friends cordial greeting
I have a Milexus ML-T21PF TV flashing led stand by and it does not turn on and sounds toc toc speakers
The source voltage C806 are in 172 to 180V oscillates. pass the same with the voltages of + b and the rest after the chopper
remove the + by and stabilized C806 in 170 171V
D842 10.9V
D841 11.4V
D833 106.1V + B
IC801 pin 1 11.3V and pin 8 162V
Q815 Rector D 161.7V and G0.4V
Check optocoupler and ok and change Change the C845 of 100 / 16V that was regular and nothing
Will source problem of IC801 be?
Grace
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Curso Localización de Fallas en Refrigeración en Heladeras/Neveras On/Off
