Everything about displays and monitors. 120Hz, 144Hz, 240Hz, 4K, 1440p, input lag, display shopping, monitor purchase decisions, compare, versus, debate, and more. Questions? Just ask!
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LagBuster
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by LagBuster » 08 Mar 2020, 06:32
A few months ago I bought an off-brand 4K monitor. It was particularly cheap because it had a visible vertical line defect and it was seemingly a permanent defect. So I thought: "for what I paid for it I can live with it, it's no big deal." But to my surprise, recently this vertical line started to "flicker" and now it's barely visible.

I mean, I'm not complaining because now the line is almost invisible and it stayed that way ever since.

But I'm still interested to know what this is all about, if anyone knows. Video below of the moment it decided to "flicker".
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Chief Blur Buster
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by Chief Blur Buster » 09 Mar 2020, 13:58
LagBuster wrote: ↑08 Mar 2020, 06:32
A few months ago I bought an off-brand 4K monitor. It was particularly cheap because it had a visible vertical line defect and it was seemingly a permanent defect. So I thought: "for what I paid for it I can live with it, it's no big deal." But to my surprise, recently this vertical line started to "flicker" and now it's barely visible.

I mean, I'm not complaining because now the line is almost invisible and it stayed that way ever since.

But I'm still interested to know what this is all about, if anyone knows. Video below of the moment it decided to "flicker".
It's hard to see, so single-frame-stepping is easier (YouTube , and . keys)
This would probably be a borderline panel defect. One pixel column addressor glitched -- possibly address-line corruption or something similar that caused one vertical pixel row to go all black (zeros) for a single refresh cycle. Noise in address lines or data lines could have caused that to happen. In extreme situations, it causes flickery vertical lines, much like well-worn scratched 35mm film.
Testing this with overclocks (61-65Hz) and underclocks (55Hz) could create some intersting effects -- like decreased incidence or increased incidence.
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LagBuster
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by LagBuster » 13 Mar 2020, 09:00
Chief Blur Buster wrote: ↑09 Mar 2020, 13:58
This would probably be a borderline panel defect. One pixel column addressor glitched -- possibly address-line corruption or something similar that caused one vertical pixel row to go all black (zeros) for a single refresh cycle. Noise in address lines or data lines could have caused that to happen. In extreme situations, it causes flickery vertical lines, much like well-worn scratched 35mm film.
Testing this with overclocks (61-65Hz) and underclocks (55Hz) could create some intersting effects -- like decreased incidence or increased incidence.
Hi Chief, sorry for the late reply. The line is almost completely gone now, it got even smaller and "fainter" since I wrote the OP - I can barely even make it out with my eyes now and I have to get real close to the screen and search for it, to the point where if I asked someone to find it I'm pretty sure they wouldn't be able to. I wonder if it's possible that it disappears completely and permanently by itself? I didn't do anything to it other than overclock the monitor from 60 to 62.9 Hz.
Another thing is that the line is purple, not black. I know that R+B makes purple. And what I mean by "it was seemingly a permanent defect", is that it stayed there the whole time, i.e. it didn't flicker until the moment it did when I recorded the video. Since then or before that it hasn't flickered, but it has gotten smaller like I said.
Anyway, I'm amazed by this.

Last edited by
LagBuster on 13 Mar 2020, 12:34, edited 1 time in total.
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Chief Blur Buster
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by Chief Blur Buster » 13 Mar 2020, 09:30
Temperature changes and panel settling can make a big difference in this kind of borderline defect.
That said, a tap on the monitor could also worsen things for this "electronic circuit equivalent of a loose wire" -- so be careful when moving around the monitor.
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LagBuster
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by LagBuster » 13 Mar 2020, 12:10
Chief Blur Buster wrote: ↑13 Mar 2020, 09:30
Temperature changes and panel settling can make a big difference in this kind of borderline defect.
That said, a tap on the monitor could also worsen things for this "electronic circuit equivalent of a loose wire" -- so be careful when moving around the monitor.
Alright, thanks! I'll be careful.

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LagBuster
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by LagBuster » 13 Mar 2020, 12:27
This is what it used to look like, btw.

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Chief Blur Buster
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by Chief Blur Buster » 13 Mar 2020, 19:11
Yes, be careful moving around the monitor.
The "electronic equivalent of a loose wire" is usually embedded inside the glass or panel so it is not user-fixable, and probably not professionally repairable either. If it happens again, and your warranty is expired, and you have nothing to lose by opening the monitor, then gently squeezing the panel or panel edges (from both behind and in front, after opening up monitor) sometimes fixes this problem if this reoccurs. But can worsen things. Something you can do as a last-resort for an expired-warranty monitor.
The great news is that this fixed itself, hope it stays fixed!
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LagBuster
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by LagBuster » 14 Mar 2020, 11:06
Chief Blur Buster wrote: ↑13 Mar 2020, 19:11
Yes, be careful moving around the monitor.
The "electronic equivalent of a loose wire" is usually embedded inside the glass or panel so it is not user-fixable, and probably not professionally repairable either. If it happens again, and your warranty is expired, and you have nothing to lose by opening the monitor, then gently squeezing the panel or panel edges (from both behind and in front, after opening up monitor) sometimes fixes this problem if this reoccurs. But can worsen things. Something you can do as a last-resort for an expired-warranty monitor.
The great news is that this fixed itself, hope it stays fixed!
I hope so too and I'll keep that in mind! Thank you for your kind input.