Dell U3014 - discoloured corner, shadow

[Pete9-3]

I have acquired this monitor few months ago with dying backlight strips. Fitted new ones and all was good for a month or two.
Out of sudden issue poped up with right top corner being discoloured, sometimes it looks like colours being reverted, lighter instead of darker etc. Also picture is not so smooth towards right edge of the screen, with horizontal lines being visible, and slightly dimmed.
When system boots up instead of apple logo I get white vertical line in its place going from top to bottom.
Apart from this monitor seems to be working ok.

[Topcat]

Re: Dell U3014 - discoloured corner, shadow

I'd take it apart and make sure all your LVDS ribbons are clean and seated well....

[Pete9-3]

Re: Dell U3014 - discoloured corner, shadow

Will do. Can I use Isopropyl on these?

[Topcat]

Re: Dell U3014 - discoloured corner, shadow

Will do. Can I use Isopropyl on these?

Yes.

[Pete9-3]

Re: Dell U3014 - discoloured corner, shadow

These cables were sitting tight. I have removed and cleaned them but nothing has changed at all.
Any other suggestions please?

[Topcat]

Re: Dell U3014 - discoloured corner, shadow

These cables were sitting tight. I have removed and cleaned them but nothing has changed at all.
Any other suggestions please?

Not really, other than taking the panel apart again and making sure a LED bead isn't wonky; causing the discoloration....but that wouldn't cause the lines.

[Pete9-3]

Re: Dell U3014 - discoloured corner, shadow

Any clue whether it could be panel or electronics?
I've tried to press any visible ribbon when monitor was on, nothing has changed again. It didn't get better or worse what makes me hope it is not a panel.
Also picture seems to be divided in four horizontal bands on the right side with every band being darker at the bottom of it. I assume it would be hard to explain such an discolouration caused by backlight LEDs?
I would appreciate any suggestions as it seems to be decent monitor.
I must admit that stripping the panel again would be a pain but can be done if need be.

[Topcat]

Re: Dell U3014 - discoloured corner, shadow

Any clue whether it could be panel or electronics?
I've tried to press any visible ribbon when monitor was on, nothing has changed again. It didn't get better or worse what makes me hope it is not a panel.
Also picture seems to be divided in four horizontal bands on the right side with every band being darker at the bottom of it. I assume it would be hard to explain such an discolouration caused by backlight LEDs?
I would appreciate any suggestions as it seems to be decent monitor.
I must admit that stripping the panel again would be a pain but can be done if need be.

It's hard to tell, it could be either....but the seat of my pants says tab bond or tcon issue....maybe you got a little rough with it when changing the LED's initially. Tab bonds are damaged very easily, they're not repairable....so if that's the issue, the panel essentially is toast....but I would still recheck every connector inside that monitor.

The discoloration I've seen a few times, typically pressure points (twist in the panel) or as already suggested; a wonky LED bead.

FWIW, I have a fleet of U3011's that I'll never part with until I just can't fix 'em no more! This was the last CCFL model before the 3014 and LED backlighing.... So very reliable!

[Pete9-3]

Re: Dell U3014 - discoloured corner, shadow

I have tested a bit further today. I have re-seated all cables between boards, and ribbons between little board stuck at the back of a panel and drivers if i can call it like that above.
I've dismantled panel again and lifted lcd up to see nice and even backlight underneath. Doesnt look this causes an issue.
I rubbed along these tap bonds how you called them when monitor was on at both ends and was trying to manipulate them gently to see eventual issues.
None of these have made any change. Visually it is all in good condition.
I have measured few voltages but have nothing to reference to. Do you have any sort of schematic for either this model or one before by any chance?
I have also taken few additional pictures as few things might have been described incorrectly before.
First of all this discoloration in right corner is not permanent to start with. As you can see in attached photos at the beginning with blue background issue is not visible, or barely visible. Once something light coloured land there it becomes worse. Also you will see that side bar in app window is causing ghosting line above same as mouse cursor. I have also noticed image retention after light coloured objects being placed in this corner.
Even menu at the bottom causes visible artefacts at the top of the screen.
I am trying to add a video but not sure how to.
Does it still look at broken panel to you?

added video link: https://photos.app.goo.gl/AxJ9irEGF9EousLdA