fixing possibly a bad power supplies board of a LED TV

Thread Starter

Leon_Chan

Joined Sep 11, 2019
81
Suppose you have a bad LED TV with its power supplies board damaged. And this board is no longer available for sales. So how should you choose another similar power supplies board to replace it. What specifications you need to look at?
 

LesJones

Joined Jan 8, 2017
2,672
It is very unlikely that you will find a power supply board that will replace the original. It will have been designed to power that particular TV set. (It will not be a power supply bought if from a power supply manufacturer.) It will either be made by the TV manufacturer or made by another company (Possibly a power supply manufacturer.) to meet the TV manufacturers requirements. That company will NOT sell it to anyone else.

Les.
 

Thread Starter

Leon_Chan

Joined Sep 11, 2019
81
As all know, the LED TV consists of several components and one of which is the board that provide power.

It is possible that the manufacturer make similar board (they don't make the old one model but make improved new ones) but what specifications of this type of LED Power board you would need to check it for compatibility.

Once a time, I got a board that they said is a replacement but find that the pin outputs are not in the same order. So when you find a replacement, you have things to consider.
 

bwilliams60

Joined Nov 18, 2012
1,325
Why dont you send the board out and get it repaired if you want to keep the TV. Otherwise, scrap the TV if you cant find a replacement. Try shopjimmy.com
They may have the board you are looking for.
 

Thread Starter

Leon_Chan

Joined Sep 11, 2019
81
Most supplier will ask for a high price if it is out of warranty. There are far more brands than those famous big one.

Get a compatible replacement may be cheaper. Also, practice doing some troubleshooting with your device and improve your knowledge and skill.
 

MisterBill2

Joined Jan 23, 2018
6,365
Suppose you have a bad LED TV with its power supplies board damaged. And this board is no longer available for sales. So how should you choose another similar power supplies board to replace it. What specifications you need to look at?
To make the LEDs light with a substitute supply you will need to know the current required and the voltage required. Excess current capability will not hurt anything, but the voltage is important. So to be the most effective you need a regulated current power supply. But what you can find that will work is an adjustable regulated voltage supply and a series resistor. Cheaper and easier to find.
 

Thread Starter

Leon_Chan

Joined Sep 11, 2019
81
Finding a replacement for ayp250008. Try google it. Also, try finding if ayp250009 is a good replacement and what are the difference.
 
Last edited:

wayneh

Joined Sep 9, 2010
16,398
My experiences are more positive than the other posts here. The last couple TVs I repaired both used standard 12V DC power supplies. Maybe 2A current rating. I replaced them with 4A rated supplies, which you can get for under $10.

But some TV power supplies are under control of the main computer IC. These are tightly integrated into the function of the TV with feedbacks and so on. No way to swap out.
 

LesJones

Joined Jan 8, 2017
2,672
Hi wayneh,
The TS does say "power supplies board " so I assume it is an internal power supply with multiple voltage rail outputs. If it is an external power supply then I agree with you that it should be easy to get a suitable replacement.

Les.
 

MisterBill2

Joined Jan 23, 2018
6,365
Of course if the failed board is only a power supply board then it is just one or two failed parts. Very often the parts that fail are the electrolytic capacitors, since they are usually poor quality and always one of the highly stressed components. So sometimes just replacing them solves the problem.

How do you know that the failure is in the power supply board? Or is that just somebody making a guess? I see a lotof guesses and many of them are incorrect.
 

Dodgydave

Joined Jun 22, 2012
9,209
The pcb is a separate one giving 12V and 5V supplies. You could try using an Atx psu just to try and see if the tv works, then concentrate on the psu board.


free-shipping-100-test-work-for-PW52057A-PW52057B-power-board-12V-5V-AY050D-2SF03-04.jpg
 

MisterBill2

Joined Jan 23, 2018
6,365
Post #1is asking about what specifications are needed to find a replacement. For the exact replacement one only needs the part number, but the exact replacement is stated to be not available.

Therefore, the specifications required, once again, are the voltages and currents needed for each of those voltages. Since it is an LED type of set, it is possible that only the LED backlight part has failed. That failure is rather frequent.
So what is needed now is more information from the TS about the failed power supply, and what voltages are required. On some products it is very fortunate that the voltages are printed on the circuit boards. Others have no labeling at all, probably because the builders do not consider their products worth repairing.
 

Thread Starter

Leon_Chan

Joined Sep 11, 2019
81
1. The power board is ayp250008. And some information or photos can be found from google as below.
Is it possible we can get a spec sheet of it and where? Or do we need it?
From the photo here, the blue and brown wires are external ac source. And the white connector with wires going out to other components of the TV.

2. I seem to have seen a swollen capacitor so I suspect the power board is bad. If I replace it and it is fixed, then it is the power board damaged. Until I got a photo of it again later.

ayp250008.jpg
 

Thread Starter

Leon_Chan

Joined Sep 11, 2019
81
The pcb is a separate one giving 12V and 5V supplies. You could try using an Atx psu just to try and see if the tv works, then concentrate on the psu board.


View attachment 205682
Looking at the output pins labelled on the photo of power board you provided.
they are:

5V
5V
GND
GND
GND
12V
12V
12V

So that is what we needed to know about this power board?
And by measuring the voltage across these pins accordingly, I can prove that the board is working or not?
 
Last edited:

shortbus

Joined Sep 30, 2009
7,768
I've repaired a couple of TVs using "kits" from Ebay. If you look there for the actual TV brand and model number instead of a board number you may find a kit for yours. Many different brands use the same power supply and most of the fail from bad capacitors, there are sellers that have made up kits of parts to fix the problem.
 

sagor

Joined Mar 10, 2019
215
Bottom left of the picture, near the line input, shows the rating, +5V at 2.5A and +12V at 2.5A. Only remaining issue is to find a PSU rated for the same input voltage, and of at least the same output ratings that fits. Then, you need to figure out the +5V and +12V output connections.
Good luck.
 

wayneh

Joined Sep 9, 2010
16,398
For testing, I'd use a computer PSU to provide the two voltages. If you've got a couple power supplies (AC power adaptors) laying around, that would work also. Just be sure they have ample current ratings.

Be very careful mapping out the voltages so you can put the right voltage onto the right wires.

If you can rig it up and the monitor works, then you know you just need to buy AC adaptors. For an example here's the last one I bought for an old game machine that held a 22? inch LCD monitor. It was $10 but appears to be unavailable right now.
https://www.amazon.com/gp/product/B06Y64QLBM

I don't recommend fixing the old power supply unless you really enjoy the challenge. Replacing it entirely is much faster and cheaper than ordering parts and doing the work.
 

MisterBill2

Joined Jan 23, 2018
6,365
Now that both the current and voltage requirements are known, 5 v @2.5 amps and 12 V @2.5 amps a commercially made supply could be acquired and connected and if it was a failed power supply then problem solved. BUT FIRST the TS needs to verify that the voltages are not being supplied, and that the problem really is the power supply board. The last TV I touched that had a failed power supply board actually had a failed remote control receiver module. It was an incorrect diagnosis by an incorrect person.
AND most often, it is the backlight driver that fails.
 

Thread Starter

Leon_Chan

Joined Sep 11, 2019
81
The pin arrangements are printed on the back of the board:
IMG_20200430_163849.jpg
GND
GND
5V
5V
GND
GND
GND
12V
12V
12V

The region near U3 above the yellow component appears dark and so I suspect if this is damaged.

To prove if it is damaged, we just need to measure the voltage across these pins, right?

The checking of this may be done *next week*.

IMG_20200430_163948.jpg
 
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