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Hello again my dear friends and we are back with the video number 3
of the screen repair Mark AOC model LE32W454F
Those who have already followed this tutorials have been able to realize the fault that I was representing this TV
which is only Reflej ABA a flash of light showed the logo of the brand and
the TV entry in protection
in the video number one we worked on the card
and verified that everything worked properly we did the corresponding tests
and verified that the breakdown was in the Backlight controller
in video number 2 We work to the backlight controller circuit we
verified the voltages necessary for the integrated controller to work
we checked the other components and we could realize that
the TV was shutting down By overload
indicating then that the power voltage for the LED challenges is too high Okay
being so this TV monitors the voltage by activating the protection circuit
by pin 12 marked as OVP
then we in this video Tutorial we will seek to resolve the breakdown
we have already mentioned in other tutorials that
For us to modify the output voltage towards the letters LED
is necessary to manipulate the voltage drop resistances found in the leg number 3 of the MOSFET
in The side where these led strips have the return
which constitutes what would be the negative pin of that led strip
but this controller as you can see
is connected directly to the integrated
then we in this video tutorial we will teach a Additional technique
which if you apply it correctly you will be able to solve this and other failures
very well gentlemen who have not subscribed to the channel I invite you to do so
and activate the Bell notifications
and also can support the channel of the way The one we are asking lately Okay then proceed to continue with the tutorial.
Very well in this situation we are going to work directly on the line of protection
if we locate here we can realize that
this voltage that is directed towards the LED strips is monitored by pin 12
and the resistances involved with this Circuit because they are only this two
means that the test that we are going to make here is the following
this would be manipulating these resistances
what we are going to do is focus directly on this resistance marked as R4
according to this Simplified diagram This resistance of 10k ohms
Therefore we are going to locate directly in what is the card we will look for that resistance
and we will verify the way in which we will vary these values ok
very well and so in a quick way to not lengthen Much the tutorial what we are going to do is
locate directly to find that resistance
and we do this by following the track printed circuit from PIN number 12 of this controller
then if I do this I can realize that exactly that line connects Directly towards this resistance
I will therefore proceed to remove it.
Very well on this side we have the resistance and how you can see is a resistance of 2200 ohms
Okay that's the original resistance of this card
and what we're going to do mainly to start changing the corresponding value
this would be doubling the value and Thus perform the corresponding tests and see what is the difference that I mark this voltage
therefore I have here this card where I can extract the resistance and here I have a resistance of 4700 ohms
Therefore I will remove one of this and I will place it in place And we're going to do the first Test.
Very well I have correctly placed the resistance now what we are going to do is take reading
the important thing here is that we monitor how much has reduced the voltage of which we are speaking
very well how you could see reached 55 volts or low too
now the next Test We're going to do is reduce the original value and if the original resistance
the original is 2200 we will place a slightly lower resistance
on this side we have another resistance that is 1500 ohms
a very suitable resistance for us to do the following Test
okay I'm going to remove it from here I will place corresponding site and we will do the following test
very well there because I have placed and now we will do the same We will monitor this voltage
commonly these screens work with 80 volts
and putting this resistance we will verify this voltage we have now
and putting this resistance we will verify this voltage we have now
and if you can appreciate the background I see that the LED strips already Did not turn off
so the TV no longer went into protection
means that if this type of cards works with 80 volts
then with this voltage we now have 73 then it is OK
but we will reposition the resistance that we had previously Removed from what is the voltage drop of the DC DC converter
and we will check how much is the voltage that normally stabilizes here okay
very well
there because I have connected correctly now we will monitor the voltage
again we will press the Power key
and How you can see 73.7 volts means that the voltage has remained stable
and the LED strips as correctly lit
means then gentlemen that in the way in which we have applied this technique
as the fault has been resolved
how you can see exists is The one that teaches in other videos and many more
that we can apply to find solve the faults in this type of televisions
this is the same technique that you can apply when you find damaged LED strips
and you want to reduce the voltage so that they do not burn again
Very well how can you see there we have the resistance which we have been manipulating
we have the resistance of 1500 ohms
and the voltage that is giving us now the controller of the backlight because we see that it is a voltage that is stable and correct
therefore we will Connect the TV again to the mains electrican
we will press the Power key and thus verify how the LED strips illuminate in this screen
ok
here I have not removed what is this cover of this same TV
because it is found what are the connectors for function pushbuttons and voltage feed
but the important thing is this how you can see the LEDs have lit correctly I'm going to lift it so you can see the screen
and how you can observe the light that is reflecting the LED strips because it is very very good
ok
ok we will only need to solve the problem that this screen is stained or dirty internally
ok
but this is an additional job
I will generate another tutorial where I will show you a liquid that you can use to clean these layers
Okay but that we're going to do R in the following tutorial
so far gentlemen we can see that this fault we have solved in an easy and simple
then gentlemen see you until the next tutorial.