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Repair guides and support for your Philips TV.

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Why is my Philips TV screen is so dark?

Hi,

I've got a Philips 50PUS6162/12 UHD smart led tv and it's brightness has become very low this week. I mean I can see the menu, broadcast etc. but only in a dark room. The brightness is set to maximum in the settings and I reset it to factory settings as suggested but nothing changed. Sometimes the lower third of the screen is works fine for 1-2 minutes and than goes dark. I've measured the voltages on power board and they seems to be correct (as googled for some standard voltages). I've read that it may be T-Con that is causing the problem if led strips works, power seems right and every other thing seems good.

The warranty has just expired so please help :)

Thanks

Update (01/10/2020)

Thanks for your advices. In this case dark means I can see the picture when (at least) there is twilight in the room or I cover the screen from reflection.

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It’s brighter on the picture than it really is. (My camera overcorrect brightness).I checked all the connectors, and reseated the wires. I also checked the boards for cold solder soints, bloated capacitors etc, but everything is good. I measured the voltages on power supply and the strip voltages are 37.5-38 V on every pin. The other connector (the upper) voltages must be 12 V and 3.5 V according to the inscription but there is nothing on 3.5 V pin. That is the only fault.

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So I still don’t really know what’s wrong with it.

Update (03/01/2020)

Thank you @oldturkey03

I took some pictures as you requested.

I took two pictures of the display, one at daylight and the other in a darkened room, to see the difference.

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I checked the connectors and reseated all of them but nothing has changed.

All of the LED connector voltages on the power board are 37.8 V.

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I also made some pictures of the boards:

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If the backlight is faulty, may all the LED strips go wrong at once?


Update (04/24/2020)

So after T-con, I replaced the power board too, but it’s still the same. Dark... Voltages are similar to my original power board so I guess it isn’t faulty.

What’s next? Should I disassemble it completely to the led strips, and power them manually?



Contestado! Ver respuesta Yo también tengo este problema

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Hi,

Have you checked the connections between the power board and the backlights?

It sounds more like a backlight problem as the TCON usually feeds vertically and you say that the lower third of the screen works for a bit and then goes dark.

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Yes, I checked all the connections.

I don't know if it's matters, but once I touched the bottom center of the tv (the frame) to lift it up, the whole display worked fine just for some seconds.

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I just replaced the T-CON board and nothing changed. What should I do next?

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Got the same problem, no backlight. Did you dismantle the LCD panel and check the backlight array yet?

Thanks.

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Did u fix it and how?

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Solución Elegida

@sigurdur The led strips caused the problem. At the end the tv was fixed by a professional workshop because after I replaced the power supply, T-CON board, checked all the wires and solder joints, it still didn't work. It makes sense since every function worked properly, only stips could have caused it.

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Patrik Bajusz  that will depend on how dark is dark. If your backlight have totally failed you will usually need a flashlight etc. toe even make out shapes or silhouettes. In your case it could be a power board not supplying enough voltage to the backlight LED’s or, based on this “once I touched the bottom center of the tv (the frame) to lift it up, the whole display worked fine just for some seconds. “ some loose connection to the backlights. Check all of your wires by reseating them. Check the boards for cold solder joints. There is also a slight possibility that this is the T-con board since it could be a failed Gamma IC which could darken your screen.

Update (01/10/2020)

@Patrik Bajusz post another picture showing the whole display. The #1 picture does not give us a good overview. Did you check the connections as suggested in my original answer? What did you find? What voltages do you get on your LED connector on the power board? We also need to see all of your boards not just a single connector. Help us to help you.

This "Sometimes the lower third of the screen is works fine for 1-2 minutes and than goes dark. " by itself sounds like some bad backlight strips.

Update (01/10/2020)

Patrick Bajusz this "voltages on the power board are 37.8 V" looks a bit low. It's easiest to replace a bad power board. If that does not fix it you know its your backlight array and you will have to replace those by dismantling the LCD panel

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that is a bad backlight board. sometimes a strip can be fixed but if not , replace the led strips and that fixes it

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