fixing possibly a bad power supplies board of a LED TV

MisterBill2

Joined Jan 23, 2018
6,329
Now there is a test that the TS can do with no electronic test equipment and no circuit. That is to power up the set and shine a bright flashlight into the panel at an angle. If the set is working except fore the backlight, there will be some evidence of a picture. Mostly, what failes on a TV is the backlight. either the power supply or the controls.
 

Thread Starter

Leon_Chan

Joined Sep 11, 2019
81
I will always pick the cheapest with accepted quality. But for the riches and these who buy for their organizations, they cannot spare the time to fix anything or accept down time, just call for the big brand service support immediately.
 

MisterBill2

Joined Jan 23, 2018
6,329
I will always pick the cheapest with accepted quality. But for the riches and these who buy for their organizations, they cannot spare the time to fix anything or accept down time, just call for the big brand service support immediately.
The challenge is always about the quality. I asked a sales person about the quality one time and the dude immediately claimed the product was of the highest quality because of all the features. I explained that quality was all about how long it would work before breaking, at which point he started explaining about all of the service plans that I could buy so that it would be fixed for free when it broke. The price of the service plan would have covered the cost of a much better product elsewhere. I had to explain that quality means a product is built to last, which was a concept that person did not understand. I left without purchasing anything, and have not been back in 15 years.
Quality in things like a TV is related to both the quality of the parts and the stress levels that they are operated at. That can be learned by noticing which brands are seen at the curb the most on trash collection days. When new-looking sets of a brand are frequently seen, it becomes clear as to where the quality is not found. This may not be a fair or scientific evaluation, but it does make sense.
 

Thread Starter

Leon_Chan

Joined Sep 11, 2019
81
Now there is a test that the TS can do with no electronic test equipment and no circuit. That is to power up the set and shine a bright flashlight into the panel at an angle. If the set is working except fore the backlight, there will be some evidence of a picture. Mostly, what failes on a TV is the backlight. either the power supply or the controls.
Nothing found displayed.

A normal LEDTV will have its IR light red when ready and blue when you power-on its with the remote controller or panel buttons.

I find the light is red but the remote controller cannot operate it on or off. Sometime I can start it with the blue light, but the remote controller still do not work. So it is believed that the TV hangs while it is loading.
When this LEDTV failed, it show a logon screen while loading and hangs. The other day, its failed to display anything too.

Is there any other kind of use to this LEDTV remained in this mode of failure?
 
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Thread Starter

Leon_Chan

Joined Sep 11, 2019
81
To me that says the remote is dead. What happens if you use the on switch built into the TV?
No. That means the board is not functional.
I can detect the remote controller signal with a camera lens.
Not sure if this is caused by a bad LED Driver board and I am now focusing on it.
 

Thread Starter

Leon_Chan

Joined Sep 11, 2019
81
The LED driver board has following printed on it.

hq-led07k
20110603003416
94V-0
1052
D E300052
I have not found the same board so I have to get a cheap replacement or trying to do fixing on it, for example, replace any capacitor on it???
 

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MisterBill2

Joined Jan 23, 2018
6,329
The LED driver board has following printed on it.

hq-led07k
20110603003416
94V-0
1052
D E300052
I have not found the same board so I have to get a cheap replacement or trying to do fixing on it, for example, replace any capacitor on it???
Before replacing the remote control board you should check first that the remote board has power, because if it does not have power then there is a problem someplace else. If it does have power, then you can use your DVM on an AC range to check the other leads from the remote board to see if any digital data is sent when you operate the remote control.
If the set does not have an on/off switch on the TV itself then I would just scrap the set. In my evaluation any TV that is only controlled by the remote is trash. That is because the remote control is quite prone to failure.
 

Thread Starter

Leon_Chan

Joined Sep 11, 2019
81
As mentioned in #45, but it is more clear to mention again that both panel buttons and the remote controller cannot operate the TV after it is plugged in and with the IR light goes red/ready. It cannot switch it on or off the TV( to turn its IR light to blue). It is simply hang.
Now I am focusing on the small LED driver board that some people saying "replacing it had his TV fixed".
Get a compatible replacement or do some test/fix on that exist one.
 

Thread Starter

Leon_Chan

Joined Sep 11, 2019
81
There is not the same LED driver in the market now. Anyone can provide advice on how to choose a compatible LED driver as above. What specifications I should be taken notice of ? Thanks
 

Thread Starter

Leon_Chan

Joined Sep 11, 2019
81
As I cannot get a cheap LED driver replacement providing 1050mA to test it further, and it is tested that the power supply is not the suggested problem, the thread of this will be closed unless there is something new, for example, understanding enough about how the LEDs work and its calculation in future.

I think it may be possible that both the LEDs and the LED driver is replaced as a complete set, which can be bought in the market, however.

There is little value to fix a 10-years-old product with parts no longer ready available when new ones come at cheap price unless for practical purpose.
 

MisterBill2

Joined Jan 23, 2018
6,329
TGhe way to check and see if the problem is the LED part of the set is to have the set on and tuned to a station, or other video source, and then use a flashlight or similar light source to look into the screen. If it is done correctly it will be possible to see images in the screen dimly. That will show that the problem is only a lack of illumination. If the set can not be turned on and tuned to a station then the problem is not in the screen illumination system.
And a further note: Replacing the LEDs requires an extensive amount of disassembly of the set.
 
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