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Issue with KDL-48W600B possible LCD issue.

I have a Sony KDL-48W600B and after several different Google searches for my particular issue, I have not found anyone with a similar problem.

The TV powers up and works fine for 1 - 2 minutes, then after that time, there is a screeching noise from the back and the LCD turns on and off randomly. Sound and the rest of the TV continues to work and it seems like it is just the LCD that is being powered on and off. I have replaced the LDHM2 board thinking there was a capacitor issue on that board but it did not resolve my issue.

Below is an image of the board, the circled components are where the noise is coming from.

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Below is a short video of the sound that the board is making.

I am wondering if anyone has experienced a component board that made a noise like this or if anyone has any idea what those components are? (I’m not that experienced in working with electronic components.) Or why it would cause the screen to turn on and off like this. I know it is limited to the LCD and not the main board power because the TV continues from where it was and there is no boot up of the TV as this is occurring.

Anyone have any ideas, I have little experience with this and am not sure if there is another component between that could be causing this issue. If so is this something that can be replaced.

Thank You.

Followup image of the CN9101 pin out voltages. Not sure how the actual pins relate to the service manual’s pin diagram so the diagram on the PCB side is the row of pins closets to the PCB Board.

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Add a picture of the complete layout of your boards.

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@richnish what you hear is a coil whine coming from the fixed inductors (components you pointed out). This could be caused by to much current or something trying to pull to much and making those inducators work “overtime” Since this is a new board we can assume it is okay. Check the connector CN9101 and compare the voltages to what they should be . Let us know what you find. also, how is the screen blinking. Does it go darkl and comes back on in a sequence or just continuously on and off? It is possible that this is cause by a bad backlight array. Disconnect the cable going to your LCD screen (particular the backlight one) and see if your inductors still whine.

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Thank you for the response oldturkey03. I am not sure which connector is CN9101, is there a specific numbering sequence to the labels on the board?

Also, as to your question regarding the screen blinking, in the video, at about 3-4 seconds, if you look through the holes in the metal backing, you can see the back lights turn off then back on. I have not seen a pattern to it but it's a quick turn off then on, it stays on for 10 to 15 seconds then turns off and back on.

I have also removed the cable on the left side of the LDHM, the one that goes under the metal covering and the LCD does not power up but the coils do not make and noise with it disconnected.

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@richnish the connector should be labeled on your power board as such. This could be an issue with your backlight array since it is not in any kind of pattern.

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@oldturkey03, I don’t know how to read the pin out diagram in the service manual but I have an images of the voltages from the CN9101 connector that I have added to my question above.

If it is the backlight, will replacing the array fix it. Is there any other component involved with the backlight that can have the potential to be the cause of this issue?

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Sorry for the late reply. I replaced the the backlight array which in turn solved my issue. The TV is no longer power cycling and there is no longer any high pitched noise from the power board.

Thank you @oldturkey03 for your help!

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Richard, my Sony Bravia KDL-48W600B is making the exact same noise as the one in your video, could you please tell me how to go about fixing it? ~Mark~

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Richard Nishizawa will be eternally grateful.
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