Comments on: DVD Player Turned LED TV Panel To White

By: Parasuraman S

Parasuraman S — Tue, 02 Aug 2022 12:12:12 +0000

In reply to Imoudu.O.

We eagerly look forward to!

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By: Imoudu.O

Imoudu.O — Mon, 01 Aug 2022 19:59:28 +0000

Yogest.P
Hi,thanks for your suggestions, I will try out all suggestions in due time.For now,since I need a tv for my operation urgently,I remove the screen from the affected Sony and transfer it to another device and it came out fine.Later in the month I will look to the 32" tv and the lg DVD, and will write an article to my findings.Have a nice day.

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By: Parasuraman S

Parasuraman S — Sat, 30 Jul 2022 23:46:42 +0000

In reply to Imoudu.O.

Since both the screens are showing white, it is assumed that the standby on and backlight is ok. In most of the cases, this is controlled by the uController. So, just check whether the TV/The other video player are responding to commands from key or remote. If they are, the problem is only in the Video input, which probably is due to shorting of the protection diode. If not the video input processing stage such as an IC could be bad. Anyhow, please don't give up. Find out the culprit and report! We too are curious to know the reasons for such failure. Similarly, also please check the output from the DVD player as well and let us know!

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By: Yogesh Panchal

Yogesh Panchal — Sat, 30 Jul 2022 15:09:34 +0000

1. First Identify faulty / suspected part (DVD or TV) by segregating one by one.
2. Test the TV on some working video source.
3. Try by giving external Power source.
4. Clean the Main Board using Thinner /IPA.
5. Check if some Component is over heating on suspected unit.

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By: Imoudu.O

Imoudu.O — Sat, 30 Jul 2022 09:28:58 +0000

Mr P.S and Mr A.B
Thanks for your contributions and advice,I will look to these suggestions.Have a nice day.

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By: Albert van Bemmelen

Albert van Bemmelen — Fri, 29 Jul 2022 16:06:33 +0000

I think that it has to do with your direct AV wire connections, also known as COMPONENT, and some kind of too high voltage on your dvd video and or audio outputs. At best you could use an oscilloscope to examine the probably dangerous signals but only by using at least an 1 to 10 probe to avoid also damaging your oscilloscope inputs in the process. But before you do maybe also first measure the output voltage with your digital MM first. Normally that output voltage should be around 1V pp for video Composite inputs. And for LINE outputs −10 dBV (300 mV) at 10kΩ. Maybe see also => https://www.broadcaststore.com/pdf/model/793698/TT148%20-%204053.pdf
I hope you still will be able to repair your defect AV inputs.

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By: Parasuraman S

Parasuraman S — Fri, 29 Jul 2022 13:52:32 +0000

In reply to Parasuraman S.

I also remembered one more point. Just check whether the video in to ground is showing 75 Ohms in both the LEDs. There are Zener protection diodes in it. These get short quite often. Do the same test on the DVD player too.

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By: Parasuraman S

Parasuraman S — Fri, 29 Jul 2022 13:50:44 +0000

If excess voltage is present in the video or audio output, it can damage the internal parts of the LED TV. You did not say what happened when the DVD connection was removed and another working input was given. Anyhow, the uController might have gone to protection mode. You have to check the VGL/VGH/Vcom/AVDD voltages on the T-cob or Scalar board after ensuring the main power supply is good. All the very best. This has opened some interesting investigations for you and I am sure you will succeed in restoration and writing another couple of articles in this wonderful forum!

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