Brightening and dimming on its own

Hi,

It could be the power supply to the backlight LEDs or the connection to or in the LED strips.

The monitor would have to be opened and further tested.

If you decide to do this then if it is determined that the backlights are OK and the problem is with the mainboard it may be easier to replace the mainboard than to try and fix it without a schematic diagram.

Search online for BN41-02352B to find suppliers. The mainboard board number was found by looking at the images in the ifixit guide below. If you decide to order a replacement board please verify the board number on your board as it may just be slightly different for whatever reason.

Here’s the ifixit Samsung U28E510 Motherboard Replacement guide which will help to gain access to the board.

Alternatively contact a reputable, professional electronics repair service and ask for a quote