PB287Q Partial backlight

[KNP]

Hello Community,

I have this monitor with a backlight problem that I'd like to revive. When the monitor is cold, only parts of the backlight lights up. After maybe 30 minutes when the monitor has time to heat up, if I power cycle multiple times using the power button the backlight is sometimes restored fully.

I opened the monitor to inspect the power supply board, and even thought none of the capacitors where bulged, I replaced them anyway. But that did not fix the problem.

Any idea what might be the problem?

[KNP]

I did a bunch of probing with a multimeter and the problem is either the OZ9998HGN (4-led strip controller) or one of the led strips themselves.

I'll order first the IC and replace it to see if that fixes the problem.

[KNP · Accepted solution]

Sorry for the late reply as the thread got locked before I could post my solution and I had to ask a moderator to unlock the thread.

So, I fixed the monitor about 2 years ago. The LED strip was the defective part. It was not an easy fix because you have to dissasemble the LCD panel in order to expose the LED strip. The LED strip is also super glued to the side of the metal frame. The LED strip I got was from Aliexpress. Here is the link: https://www.aliexpress.com/item/1005005098958643.html

Two small problems though:

1- Either the LED strip is slightly too bright or I didn't reassemble the panel correctly because it's slighty brighter on the left side of the monitor where the LED strip is.

2- It looks like I now have a dead pixel but I think it's actually a piece of dust that got lodged in between the panel layers.

I still use the monitor to this day as a secondary monitor!