Sharp Aquos LC-40LE831S - The LED / logo is flashing cyclically

Hello
The TV worked flawlessly for me for several years, one time it just did not turn on (no response), I found the service manual, took a few measurements and it fell on the motherboard. Not available in Poland, that's why I ordered from the UK.
I installed it, a few times the tv started up (no image), only lighting up all buttons and logos.
At this point, only the LED in the middle flashes with a frequency indicating "lamp error"
Before I start disassembling the matrix, I would like to find out how to delete the error, because the Vol- + Prog Up combination on the touch panel does not work, the TV immediately starts flashing with the diode.

describe exactly how you make the combinations ...

I touch Vol- + Prog Up on the touch panel then put the plug into the socket

In the Aquos sharp machines, the connection cubes between the fluorescent lamps and the inverter are defective. Remove the inverter and check for any burns on the cube / contact on the inverter board. There are methods to fix this ... after repair, you need to clear lamp errors in service mode.

Check this before disassembling the die

best regards
Michael.

Unfortunately, everything looks ok. I soldered the ankle prophylactically.
The only question is how to delete the error if the symptoms are as described above?

michas wrote:

In the Aquos sharp machines, the connection cubes between the fluorescent lamps and the inverter are defective. Remove the inverter and check for any burns on the cube / contact on the inverter board. There are methods to fix this ... after repair, you need to clear lamp errors in service mode.

What fluorescent lamps ??? What are you writing.....

Added after 4 [minutes]:

Patrwoj wrote:

I touch Vol- + Prog Up on the touch panel then put the plug into the socket

Read the service manual again ...

While holding down the "VOL (-)" and "CH ()" keys on the set at once, touch the power supply key on the set

michas wrote:

In the Aquos sharp machines, the connection cubes between the fluorescent lamps and the inverter are defective. Remove the inverter and check for any burns on the cube / contact on the inverter board. There are methods to fix this ... after repair, you need to clear lamp errors in service mode

How to check fluorescent lamps on a TV with LED backlight?

Sorry, google crashed that it was an LCD TV and I was confused by the lamp error. Sorry for the confusion.


Michael

michas wrote:

Sorry, google crashed that it was an LCD TV

Because it's completely true, the so-called LED is unfortunately only LCD with LED backlight.

buli1 wrote:

Read the service manual again ...

While holding down the "VOL (-)" and "CH ()" keys on the set at once, touch the power supply key on the set

I tried too, it doesn't do anything. The diode starts flashing immediately after connecting the power, even when I already hold Vol- and Prog Up before, touching the power button does not give anything, as it flashes like this.
I tried the same after turning on the power, only press this combination

You can try to power the garlands from an external source, these diodes fall short of a short circuit from what I remember (unfortunately it happens quite often, especially when the backlight is set to max). When it shines and you have underexposed places, the diode is burnt if it doesn't shine at all, of course. You would have to use a laboratory power supply with a current limitation. You can fix the garlands by replacing the diodes or, as I think, a better method of cutting a piece of a strip from a new garland and inserting a strip with a damaged diode instead of a strip - then you do not need to move the diffusing lens. Before disassembling the matrix, I advise you to buy disposable latex gloves. When it comes to resetting the error, it is probably not possible before removing the damage, the matrix must be lit so that you can see how to navigate the service menu and what you delete.


best regards
Michas

michas wrote:

You can try to power the garlands from an external source, these diodes fall short of a short circuit from what I remember (unfortunately it happens quite often, especially when the backlight is set to max). When it shines and you have underexposed places, the diode is burnt if it doesn't shine at all, of course. You would have to use a laboratory power supply with a current limitation. You can fix the garlands by replacing the diodes or, as I think, a better method of cutting a piece of a strip from a new garland and inserting a strip with a damaged diode instead of a strip - then you do not need to move the diffusing lens. Before disassembling the matrix, I advise you to buy disposable latex gloves. When it comes to resetting the error, it is probably not possible before removing the damage, the matrix must be lit so that you can see how to navigate the service menu and what you delete.



best regards
Michas

Buddy, what lenses ??? how is the edge illumination there ...
You don't know, don't mislead .....

Added after 3 [minutes]:

Patrwoj wrote:

buli1 wrote:

Read the service manual again ...

While holding down the "VOL (-)" and "CH ()" keys on the set at once, touch the power supply key on the set

I tried too, it doesn't do anything. The diode starts flashing immediately after connecting the power, even when I already hold Vol- and Prog Up before, touching the power button does not give anything, as it flashes like this.
I tried the same after turning on the power, only press this combination

You can check the diodes by connecting the tester or if you do not have a power supply, but the voltage is about 50V ... You have 4 separate power sections ... i.e. 4 LED strips.
As soon as you know what and how will be addressed at I have such slats.

I tried the measurement with a meter set to the diode test, I measured the resistance on individual LED strips, I connected a laboratory power supply (set at 30V, because it does not allow for more), the load did not even budge

The current-voltage characteristic of a diode is such that the current begins to flow when the voltage exceeds a certain value.
You need to know the value of the voltage deposited on a single diode and how many diodes are in series. e.g. the voltage drop on the diode is 2V in series is 10 the current begins to flow when the 20V is exceeded but when you give e.g. 18.5V the current will not flow and the diodes will not light up.
I do not suggest any more today because I have a bad day and the prompts do not come out despite my best efforts

best regards
Michael

I am so shy to ask, what are the premises (apart from the repairer's guesses), evidence of a damaged backlight?

Kolego @ buli1 we are in the beginners section why to float like this boy is just learning you need a little understanding. How do you need to direct 2 times. Why introduce a tense atmosphere after all, we are all colleagues and we do what we like, and that's my view.

Quote:

I will shyly ask what are the premises (apart from the repairer's guesses)

error lamp error ??

best regards
All electronics lovers

Michael

I'm sorry, but he's not learning. He is just trying to save money on repairs (which he does not do well anyway), and he has no idea about TV electronics. In addition, it is quite possible that you introduce him to raspberries, or - even worse - you will be "responsible" for additional damage.

I added a topic in the beginner TV section, because I'm a beginner in TV. I repair TV very sporadically, this time it fell on my Sharp, it will not be possible to fix it, it will go to the trash - hard.
I do not want to repair it from savings, but from the desire to gain new knowledge and satisfaction from a possible repair. The album could not be saved because a few feet of the ic2001 circuit were burned out, instead of ordering the circuit from the UK or China (it probably wouldn't end there) I decided to order the album, which was not such a bad decision. The only thing that remains is the most likely damaged backlight.

I powered 30V because I do not have a more powerful voltage source - my mistake, because it did not have the right to give any result, if time allows, I will quickly build a power supply (a few transformers are in arrears, maybe I will find something suitable) or I will just buy an LED tester

Make a current source, two small transformers can be connected in series + LM317 should work.
best regards
Michael