Comments on: How To Completely Test LCD Inverter Transformer

By: Joshua Oloo

Joshua Oloo — Wed, 01 Nov 2023 08:26:29 +0000

Thank you very much for the article.Am working on lcd conic 32' tv with a display shutdown,All the CCFL tubes are ok except one, and it's on a standby mode .what could be the problem sir,Thanks

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By: Jestine Yong

Jestine Yong — Thu, 24 Nov 2022 08:09:52 +0000

In reply to Anton.

Hi Anton,

A dim display could indicate the LED backlight did not get enough DC voltage from the LED driver circuit possible due to LED light itself have issue or the LED driver board have problem. The sound or buzzing noise from the transformer may not have a direct impact on the display. Transformer have sound could be due to the loosen ferrite core, internal winding problem or external components that caused the transformer to produce buzzing sound. If the DC output voltages from the power supply are good (even though the transformer have sound) then we do not suspect the transformer fault. Most likely either the LED driver board or the LED backlight issues.

Jestine

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By: Anton

Anton — Tue, 15 Nov 2022 23:36:01 +0000

Hello Jestine,

I was searching the internet for a solution to my problem and I think this is the place to find it.

We are not very knowledgeable regarding these procedures but we are willing to learn and try to fix them, be patient.

My UHD TV had dim light, and the picture on the screen is barely visible only if it is completely dark in the room. Changing the brightness setting to a different value has no effect. I notice there is a buzzing sound coming from the back so I opened the case and localized it. It seems to me that the buzzing noise is coming from a piece that looks like a transformer.

I would like to know if this is a possible fix.

Thank you.

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By: Jestine Yong

Jestine Yong — Thu, 14 Oct 2021 07:47:22 +0000

In reply to Gerard.

Hi Gerard,
I have the board with me and I did took out the transformer and there was no part number written on it and the secondary winding was about 750 Ohm. Sorry I do not have info of where to source for this kind of transformer.

Jestine

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By: Gerard

Gerard — Mon, 11 Oct 2021 23:01:46 +0000

Hi,
Thanks for this info - very helpful. The last picture in this article shows a transformer that looks very similar, if not the same, core/bobbin as in my monitor, and one of the transformers in that has gone open circuit. I'm trying to find a drop in replacement. The turns ratio is 9:2400 with a secondary resistance of around 1.1k. Would you know of any suitable part numbers to source, or can you recall the part number of that transformer in the last image?

thanks
Gerard

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By: Jestine Yong

Jestine Yong — Mon, 11 Oct 2021 11:28:56 +0000

In reply to Andrea Del Corso.

Hi Andrea,

You are welcome.

Jestine

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By: Andrea Del Corso

Andrea Del Corso — Fri, 08 Oct 2021 13:47:39 +0000

Ottimo lavoro di divulgazione.Complimenti!
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Great dissemination work. Congratulations!

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By: Jestine Yong

Jestine Yong — Fri, 17 Sep 2021 04:06:11 +0000

In reply to Parasuraman S.

Hi Parasuraman,
You are welcome.

Jestine

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By: Parasuraman S

Parasuraman S — Fri, 17 Sep 2021 00:10:58 +0000

Very, very useful information on troubleshooting! Many thanks for sharing!

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By: Ulises Aguilar

Ulises Aguilar — Fri, 24 Jul 2020 18:59:57 +0000

Mr yong great info

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