Samsung LC49J890 (2019) 49" Ultrawide - White horizontal lines + ghosting in bottom quarter. T-CON board? [Help]
Hey r/ultrawidemasterrace,
Long time lurker, finally posting because I'm stumped and hoping someone here has seen this before.
My Samsung LC49J890DKEXXY 49" curved ultrawide developed a fault out of nowhere one morning. No physical damage, no drops, no bumps - just woke up and it looked like this.
What's happening on screen:
The bottom quarter of the display has persistent white/transparent horizontal lines across it. The lines are most visible on white or light backgrounds - on dark content (dark mode apps, black wallpaper) they're almost invisible, but the moment you put anything bright behind them they're very obvious.
The more interesting symptom is the ghosting/refresh lag in that zone. If I scroll content through the affected area - say a red box moving down the screen - a red streak stays burned into the previous position for 1-2 seconds before the display catches up and redraws. The rest of the screen updates instantly and perfectly. It's like that bottom section is on a completely different refresh cycle to everything else.
Above the affected zone the image is flawless. No dead pixels, no bleed, nothing. The panel itself looks perfect.
What I think it is:
Based on what I've read, I'm fairly confident this is a T-CON board failure. The T-CON handles refresh signalling row by row across the panel - if the output drivers for a specific horizontal zone are degraded, you get exactly this: zone-specific lag, ghosting, and signal bleed presenting as those white lines. The fact that it appeared suddenly with zero physical cause and affects a consistent band rather than random pixels points away from panel damage and toward a board-level fault.
The model is an LC49J890DKEXXY - part number I've seen referenced for the T-CON replacement is SG4903K01-1.
What I'm after:
- Can anyone confirm this looks like T-CON to them, or am I barking up the wrong tree?
- Has anyone replaced the T-CON on this specific model or a similar C49 series? Any gotchas in the disassembly?
- Is the SG4903K01-1 definitely the right board for this variant, or are there sub-variants I need to watch for?
Video of the fault attached in the media section, let me know if you can't view it.
Appreciate any help - this is a great monitor when it's working and I'd love to get it back to full health rather than binning it.
Final note i added, as the monitor warms up, the lines become even more faint and invisible however they start to flicker. Just added info to help diagnose.
Look at this for the TCON replacement board - https://www.aliexpress.com/item/1005004576806457.html