Horizontal black/white lines on ASUS VG248QE

[bshth]

Hello,

I have been using this monitor for about 3 months now and I noticed at the upper right coner, pixels looks like CRT monitors (feels like some parts of the monitor have lower PPI(Pixel Per Inch)). I am curretly running Windows 7 and 120hz. I am thinking this is a faulty monitor since it only appears at the top right corner, however it seems like bottom left side started and is slowly spreading as well.

this is the top left corner where it looks fine



this is the top right corner and you can see the horizontal black/white lines depending on what color near by pixel is displaying




Is there any fix for this? Do I need to send this monitor to ASUS and get this replaced? I am curious if there are any other people who had same issue as I did.

[Falkentyne]

It's the panel lottery; some have it, some don't, although most will have at least SOME very slight effect of it at best case (won't notice it without trying, on a good panel). The VG248QE and Benq XL2411T (NOT sure if the 2420T or the 2411Z use the same panel or not) have this scanlines effect, as the panel used is the exact same panel (the model should be listed at tftcentral).

It should NOT show up at 120hz if you are not in lightboost mode, though. Most monitors that have this issue only have it at 144 hz usually. Lightboost mode will usually make this show up at 100hz (more affected monitors) or 120hz (lightly affected monitors).

You can try to RMA it, but it's a lottery; only way to be certain is to try it before buying, at a place with a local pickup (and even then, you will probably need to use the strobelight lightboost hack to force LB if you can't see it at 144 hz).

The 27" panels do not have this issue.

[bshth]

Wow thanks for the quick reply
It seems like lightboost/strobelight was causing this issue. I reset strobelight setting and now it is gone. I am gonna run some test and see what exactly causes it.

edit1. I did some test and it looks like horizontal lines get worse whenever I have strobelight settings installed. I truned it off and it looks better but lines are still slightly visible.

[Q83Ia7ta]

It's know problem for 144hz monitors. I don't know what causes it but i got same on BenQ XL2411T at 120/144hz with disabled LightBoost in days when I tried LightBoost. Try to uninstall strobelight, reset to default parameters at monitor's OSD then power off PC, disconnect DVI, disconnect power from monitor and wait 5-10 minutes. Hope this will help

[Chief Blur Buster]

I don't know what causes it but i got same on BenQ XL2411T at 120/144hz

some test and see what exactly causes it.

The corner distortions are caused by fast scanout.

The faster the scanout, the less accurate the GtG becomes and you get GtG nonlinearities on the panel. This is a manifestation of this.
-- 120Hz non-LB scans out refresh cycles in 1/120sec
-- 144Hz non-LB scans out refresh cycles in 1/144sec
-- 120Hz LightBoost scans out refresh cycles quicker than 1/144sec

LightBoost uses an accelerated scanout (faster than 1/144sec) to create longer pauses between refresh cycles. This is to let the LCD panel finish GtG transitions before flashing the backlight on completed refreshes (LightBoost is a strobe backlight), before the next refresh cycle begins. So by necessity, it has to do the top-to-bottom scan faster to allow idle time between refresh cycles (for letting LCD GtG pixels settle).

It is a panel lottery. Essentially the panel is being pushed to near its technological limitations when you run them within 144Hz or LightBoost territory. The problem happens far less often, and are frequently non-existent, on the 27" TN panels. 27" TN panels are also better if you want better LightBoost color quality too. Also, BENQ Z-Series using Blur Busters Strobe Utility do not use accelerated scanout by default. (Except when using the Vertical Total tweaks (ala VT1350) via Custom Resolution, which embeds the accelerated scanout into the video signal directly rather than internally in the monitor like LightBoost does).

TL;DR: Scanline artifacts with LightBoost are common at the upper-right corner on many 24" panels. Switching monitors to a 27" LightBoost or or to a different strobe technology such as Turbo240 or BENQ BR, reliably solves the problem if this is a hugely bothersome artifact.

[Patrick]

It's know problem for 144hz monitors. I don't know what causes it but i got same on BenQ XL2411T at 120/144hz with disabled LightBoost in days when I tried LightBoost. Try to uninstall strobelight, reset to default parameters at monitor's OSD then power off PC, disconnect DVI, disconnect power from monitor and wait 5-10 minutes. Hope this will help

I know it's been 5 years since this was posted (lol), but I just wanted to say that I had a similar problem on my ASUS VG248QE, except it was just a single faint horizontal line that was only visible at 120Hz. I followed the procedure you recommended and the line is gone now

Now I'm wary of re-installing ToastyX strobelight. Does anyone know of another method I might have better luck with? It's probably just time to get a new monitor...

[fragtion]

Sorry to bump the dinosaur, but I woke up this morning, turned on my VG248QE, and low and behold.... faint horizontal white lines, some more pronounced than others. Google searched the issue and landed up here, and of course I'm a Lightboost/strobelight user against the odds so I'm guessing it's probably strobelight that caused/provoked the issue.

The difference between my experience and what I've been reading from other users is that, for me the issue doesn't go away if I switch to 60Hz, disable/uninstall strobelight, or shutdown/reboot my PC. It seems to be persistent...

What I'm hoping to find out is, do these white lines go away/fade away on their own? Or is this likely to be a permanent form of burnout? Also does this indicate that the panel is on the verge of total failure, or could I still use strobelight for fps gaming without worrying about the problem worsening further still?

My display usually goes to sleep on its own but I honestly can't remember if I woke it up from sleep this morning or if it was stuck on an image that may have caused the burn.

For now I've uninstalled strobelight in the hopes that the issue will subside on its own.

I'll be keeping an eye on it and try post any updates if the issue noticeably worsens or improves.

[Chief Blur Buster]

Although turning on LightBoost uses an internal fast scanout mode (~1/180sec at 120Hz using internal scan conversion) to reduce strobe crosstalk, and does momentarily sometimes create this known inversion artifact but it should go away when going back to 144Hz and less.

Because this still occurs at 60Hz, there is a different issue than Strobelight at play. By any chance, did you leave the LCD turned off for a long time in a cold room? Or did you use anything that used software-based black frame insertion? Also, was it possible the lines were already there super-faintly at 60Hz but you never noticed?

If the monitor was dormant or the room is very cold, try warming the monitor for an hour.

[Kertwaii]

My older XL2411T started glitching previous year in different ways after 10 years of use, but it was easily fixed by replacing a bunch of capacitors. Maybe yours need some service too
Though it seems like that also happened for brand new monitors...
In any case if it were me I would try that out if nothing else works