Samsung S24D590PL LED partial backlight problem

[ZackN]

Hello Knowledge holders.

First off, thanks for sharing all the info here, I have fixed multiple electronics by just searching the forum and finding what I needed.

Samsung S24D590PL model code is LS24D590PLY/ZA

I cant seem to find this particular one though. I bought this monitor at a thriftstore ($20) and it looked decent when plugged in to power. Once home I noticed the bottom right corner was very dim.

Upon opening it up I found that not all the LEDs are lit. Sometimes they light when first powered on but only for a moment. It is strange that it seems every other on on the right side is lit.

I have found a replacement panel but at $307 thats out of the budget.
This post here has a conversion kit from LCD to LED, could I potentially use something similar to replace my current LEDs?

Again, thank you all for contributing to my ever growing electronic knowledge!

[CapLeaker]

Re: Samsung S24D590PL LED partial backlight problem

strip the panel down ( remember the order on what goes where ) and take the backlight out. Either you have to find replacement LED's and fix the strip or get replacement strip.

[ZackN]

Re: Samsung S24D590PL LED partial backlight problem

CapLeaker, thanks for the encouragement. I had it mostly stripped down but the backlight was still in it.
I have now removed the backlight which I was surprised was only 1 led strip. It looks like 1/3 of the LEDs dont stay on. They will flash, then there will be a tiny tick from the board and then they will turn off. How can I determine if this is a LED issue or a board issue? Is the voltage supplied by one supply and divided or is it three separate transistors (is this the right name) that supply power to the strip?

I have done some quick googling but have not turned up any replacements, just out of stock inventory from a bulgarian website.

On the front it reads (I think)
M2LE-236SMD-R2C132171
94v-0 1443

and the sticker on the back reads
PB4009940
236AJTS

[ZackN]

Re: Samsung S24D590PL LED partial backlight problem

It looks like I might be able to make this set work. I don't think there is room in the bezel for 2 sets of LED strips but I will see once it arrives. I should be able to find a 12v source and can just pull the control pin on the original led output. I would rather find an actual replacement strip though. I will post and update how this works so that other searching can do the same or avoid.

https://www.amazon.com/Highlight-Dim.../dp/B00XFXM4NA

[momaka]

Re: Samsung S24D590PL LED partial backlight problem

It looks like I might be able to make this set work. I don't think there is room in the bezel for 2 sets of LED strips but I will see once it arrives.

Well, worst case scenario, maybe you'll just run one of the LED strips inside the case of the monitor if there is no room to fit it anywhere else... or extend it outside the monitor to light behind the monitor. (That is, if the LED kit board cannot run with one set of LED strips disconnected.)

I will post and update how this works so that other searching can do the same or avoid.

Thanks, that will be much appreciated. It's contributions like this that keep the information on these forums useful.

As for the LED strips on Amazon... from what I've heard, those cheap LED strips (well, maybe not the particular ones in Amazon, but just in general) actually last longer than the original monitor strips sometimes. As for how the monitor will look with them, that's another question - especially in your case, if you happen not to be able to fit both LED strips in the monitor frame.

[ZackN]

Re: Samsung S24D590PL LED partial backlight problem

I am having trouble finding a proper power source for the new LED strips. It looks like they require between 9 and 30v input. The original output on the stock LED seems to be 34v.

I was testing the original LED strip and noticed that the three sets were reading 33.8, 34, and 35V. When not plugged in to the strip the power seemed to measure about 6.6V. This confuses me, is the board regulating voltage to the strip or is something amis on the board causing the voltage to be slightly different for each set of LEDs?

Pictures of the back and front of the board.

Thanks all for the help, I am finding electronic repair more difficult than mechanical repair.

[momaka]

Re: Samsung S24D590PL LED partial backlight problem

This confuses me, is the board regulating voltage to the strip or is something amis on the board causing the voltage to be slightly different for each set of LEDs?

The board is not regulating the voltage, but rather the current that goes to each strip. For better efficiency, this is typically achieved with PWM control... so the voltage over each LED strip is NOT a steady DC value. Therefore, you cannot really measure it accurately with a multimeter.