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View Full Version : G751 - How perceptible/imperceptible is your inversion flicker?



bsod
12-05-2014, 11:20 AM
Hey all,

So I finally figured out my flickering issue due to the particular inversion pattern my G751Jt-CH1 display uses. I first noticed it when browsing unigine.com for the gpu benchmarks. Their website background is pretty much the same as the row inversion pattern and causes noticeable heavy flickering on my display.

But I don't know if my unit is just faulty and has poorly calibrated voltage differentials for the display ? Or am I more sensitive to such flickering? Or is it the brand/model of my panel that seems more susceptible to flickering?

Inversion flicker can be tested at http://www.lagom.nl/lcd-test/inversion.php
My g751jt with a LG LP173WF4-SPD1 panel at the default 60Hz refresh flickers moderately(to me) on pattern #5, heavily on #7a, and lightly on #7b.
Also the flicker exhibits most heavily when brightness is at 100%. At the lowest brightness setting there is no flicker.

Just trying to get a feel of how off calibration my unit may be, or if there may be a model with better panels installed? Perhaps this is an excuse to upgrade to a G751JY? :D
So far my work around is to set a custom refresh at 74Hz or higher.

Richdog
12-05-2014, 12:15 PM
All G751's have the same panel type, as far as I am aware. I notice no flicker on mine.

joshindaphils
12-05-2014, 02:51 PM
I dropped back down to 60Hz on my panel and did notice a very slight flickering on the pattern, I wouldn't of likely noticed if not looking for it. It was only in the upper right of the screen for some reason.

On the plus side when viewing at my now default 100hz for the panel it is rock solid.

bsod
12-06-2014, 07:08 AM
Stopped by Best Buy today, but unfortunately they only had the 751JM touchscreen on display. That screen was pretty rock solid without any flicker. Also went around testing quite a few other brands and none of them flickered as badly as my unit, except for their mac books.
Going to see if Fry's or another store has this non-touchscreen model. But it looks like I'll be sending this one back to amazon. Has anyone dealt with laptop returns with amazon? I don't want to be surcharged a restock since I consider the unit defective if other units don't create as much eye straining flicker as this unit does.

hmscott
12-06-2014, 09:50 AM
Stopped by Best Buy today, but unfortunately they only had the 751JM touchscreen on display. That screen was pretty rock solid without any flicker. Also went around testing quite a few other brands and none of them flickered as badly as my unit, except for their mac books.
Going to see if Fry's or another store has this non-touchscreen model. But it looks like I'll be sending this one back to amazon. Has anyone dealt with laptop returns with amazon? I don't want to be surcharged a restock since I consider the unit defective if other units don't create as much eye straining flicker as this unit does.

bsod, you tried 85hz-100hz, and there is still flicker?

Amazon returns are awesome, especially if you used Prime shipping. You only need to tell them that it has a bad screen flicker and hurts your eyes.

You don't need to track down another unit to compare just to tell them that, but for your own need to compare so you know a good one can exist, Fry's is a good place to check - call ahead - Fry's just started getting them in and don't always have the JT/JY on the floor.

So you tried the JM screen on the inversion site and it looks good? Then that is a different screen - you could ask BestBuy/Fry's nicely if you can connect your USB flash drive to run hwinfo64 to check the screen make/model info.

I would be surprised if it is just your screen, but it is possible, please let us know what you find out :)

bsod
12-08-2014, 09:07 AM
yes, unfortunately that pattern still flickers pretty much the same at anything above 75Hz or so.
Well, no luck finding a display model anywhere, Fry's was all sold out of them and Best Buy only had the JM which is touchscreen so I assume it's a different panel. Flicker performance was excellent on that one and most of the other machines I tried, even the sub $300 cheap laptops.

I'm planning to return, but just afraid of worse problems in a new unit!

From the responses here so far, I'm guessing no one else has experienced any bad flicker on their G751JY/JT screens

hmscott
12-08-2014, 09:46 AM
yes, unfortunately that pattern still flickers pretty much the same at anything above 75Hz or so.
Well, no luck finding a display model anywhere, Fry's was all sold out of them and Best Buy only had the JM which is touchscreen so I assume it's a different panel. Flicker performance was excellent on that one and most of the other machines I tried, even the sub $300 cheap laptops.

I'm planning to return, but just afraid of worse problems in a new unit!

From the responses here so far, I'm guessing no one else has experienced any bad flicker on their G751JY/JT screens

bsod, the sampling is still to small to be sure, you got one response verified at 60hz, and they said there was flickering, but none at 100hz.

But, if you are still getting flicker at 85hz-100hz then that is a problem.

Why haven't you tried higher than 75hz yet??

bsod
12-08-2014, 11:01 PM
well, my panel flickers pretty heavily at 60 Hz, a very annoying pulsating thing that's across the entire screen. I've run it at 80, 90 and 100 and they pretty much look the same as 75.. as there is no noticeable decrease of the flickering for me from 75Hz and up.

I'm also finding that the subwoofer speaker vibrates horribly .. a buzzing vibration when sound is playing. It's like when computer speakers go bad and there starts to be more crackling/buzzing than actual sound. I don't know if its linked to the current subwoofer issues, but I went down as far as 50% volume and it didn't go away. My levels in the control panel are set to the default 100 so it can't be clipping I assume.

hmscott
12-08-2014, 11:22 PM
well, my panel flickers pretty heavily at 60 Hz, a very annoying pulsating thing that's across the entire screen. I've run it at 80, 90 and 100 and they pretty much look the same as 75.. as there is no noticeable decrease of the flickering for me from 75Hz and up.

I'm also finding that the subwoofer speaker vibrates horribly .. a buzzing vibration when sound is playing. It's like when computer speakers go bad and there starts to be more crackling/buzzing than actual sound. I don't know if its linked to the current subwoofer issues, but I went down as far as 50% volume and it didn't go away. My levels in the control panel are set to the default 100 so it can't be clipping I assume.

bsod, sorry to hear that, it sounds like there is a problem with the backlight overshadowing the correction of increasing the refresh. It sounds like you should return it to the seller if you can before the return period expires.

The subwoofer level control doesn't sound like it is working, part of the symptom of the audio problem with the G751, normally I would suggest starting at a level of 50 and use the AudioWizard Equalizer to correct it based on your source material having a strong bass line, but in this case it is as BRS says, it is too much of the wrong frequencies also being fed to the subwoofer and it not being able to handle the extra material without distorting - or vibrating.

I think you are the first with a bad IPS backlight, I hope your next one will be good :)

Good luck!

bsod
12-09-2014, 12:24 AM
ah, so that's what the distortion is supposed to sound like. So the sub issues is a lot worse than I imagined. Seriously annoying when you are trying to listen to a live audio feed

I did a replacement w/ Amazon so I'll be able to keep this laptop around long enough to do a side by side comparison.

hmscott
12-11-2014, 06:43 PM
bsod, if your flickering is in textures, it looks like it might be an Nvidia driver issue, addressed with Nvidia 344.80 driver Hotfix:

GeForce Hotfix driver 344.80
https://nvidia.custhelp.com/app/answers/detail/a_id/3607/~/geforce-hotfix-driver-344.80

==>> •GeForce GTX 980 displays texture shimmering when Texture Filtering Quality set to High Quality.
•GPU outputs fuzzy lines over DisplayPort after a period of time following driver updates.
•System hang up and black screen after power on with some monitors (DP1.2 & 4K/60Hz) + GTX980

It might be worth a try :)

bsod
12-11-2014, 07:52 PM
cool, let me give that a try. I'm currently running 344.74 on my 970M
I did figure out last night that the auto-contrast adjustment built into Windows 8 + the Nvidia driver exacerbates the flickering issue I've been seeing. When it goes to low contrast mode the flickering goes away, but in high contrast/brightness it flickers intensely.

I've found no way to turn off auto-contrast in battery mode yet. It seems to be a problem across all Win 8 battery operated devices (laptops, MS surface tablets, etc).

bsod
12-12-2014, 10:53 AM
I figure the texture shimmering is referring the the card's 3d aspect.
I tried 344.80 and no change to the adaptive contrast.

rmuniak
12-12-2014, 04:10 PM
Adaptive contrast? You mean brightness? There is a setting for in power setting of your system. It's called adaptive brightness - it's turned on as default option - just turn it off when in battery and you're PC should mantain same brightness level.