Database Develop

flickering screen of NC

I played with my NC nearly one week and I like it. But I want to know dose anyone notice the screen of NC is flickering. If you couldn't understand what I mean, please refer to below video,
http://www.youtube.com/watch?v=iDnBSWF44rM
it is not so obvious in real world as in video, but it is noticeable and uncomfortable. I have ipad with IPS LCD but never find this kind of issue. It like some kind of low fresh rate issue in early PC screen, so I want to know whether it is possible to fix it via adjust screen refresh rate in OS level.
Your comments are welcome!

Mine does that but only on the gray background, otherwise I don't see any flickering.

I exchanged my first NC because of this issue. The salespeople thought I was nuts until I demonstrated it for them. My new one still does it but MUCH more faintly and not all the time. I do believe that Barnes & Noble is aware of it (or at least that's something I read in another thread here somewhere..).
It seems to only happen at middling levels of brightness. My first NC exhibited the issue under very specific settings and times, the brightness had to be set between 20%-40% and I had to be displaying a solid area of mid-range colors. I saw it all the time when the screen would dim to display a menu.
From personal experience, you MIGHT be able to get a unit that's better if you exchange. It does seem to be a very common issue, though. Rumor has it that it might be fixable through a firmware update.. we shall see.

I had a pocket pc with this problem many moons ago...The fix was to adjust a trim pot on the display...
No idea if anything like that would apply here, but just wanted to mention it.

I do have similar problem, could any people advise on how to check the refresh rate and increase it?
Many thanks.

Are you planning on rooting or installing another ROM on your Nook? The overclock kernels fix this issue.

from what I see there in the video, if that is what you are seeing...not refresh rate. Rather it looks like a cycling in the backligt control. Almost looks like the PWM duty cycle is out of wack...would explain why it happens at mid range of the brightness.

My first nook color had this problem, I solved it by leaving the brightness up all the time which seemed to prevent it. I got it replaced for other display issues, and my new one doesn't flicker at any brightness, so yeah it sounds like a defect.

Not a defect. It's a problem with stupid coding in the backlight driver.
They set the PWM (pulse width modulation) rate too low, at 40Hz if I remember right. It's easy to fix by setting it up to 60Hz in the driver, which I did in my old Quickie kernel. Totally gets rid of the flicker, and I've seen no side-effects, nor have any been reported to me.
I don't have the time to keep up with the kernel anymore, and for some reason no other kernel dev has pulled my driver fix into theirs. You might talk to Dalingrin or one of the other devs if you really want it, and put them in contact with me at [email protected] and I can help them get it integrated into their kernel.

Can you link to the github commit?
Tx
Sent from my HTC Vision using XDA App

Hmmmm.... my Nook definitely had the flicker issue on most gray colors, especially at dimmer brightness settings. I'm not using your kernel, but I am using Dalingrin's. I haven't seen flicker in months. Could this issue be limited to the stock ROM only?

911jason said:
Hmmmm.... my Nook definitely had the flicker issue on most gray colors, especially at dimmer brightness settings. I'm not using your kernel, but I am using Dalingrin's. I haven't seen flicker in months. Could this issue be limited to the stock ROM only?
Click to expand...
Click to collapse
It appears that way from my experience. I was running the dual boot package with stock and CM7 nightly.
The stock rom flickered very noticeably on greyish type backgrounds. Using CM7 and now Phiremod, the flickering has totally gone away.

Actually the fix is already in init.encore.rc:
Code:
write /sys/devices/omapdss/display0/timings 68000,1024/70/200/40,600/10/11/10
That said, it's going into the driver too.

mi5 diminished parts of previously opened apps remain stuck on screen.

hello to all,
So I've recently noticed this happening on my mi5 32GB variant. Whenever I close an app, after using it for sometime, a diminished part of that app remain even after closing it.
for example, if I use FB app for sometime and when I close it and go to homescreen, near the upper part of the screen I can see the diminished part of the FB app ( the upper part of FB app) even after closing it.
This can be viewed better if I go to recent apps screen. Since it has a greyish background the image can be viewed better. This is more prominent in the upper corners of the screen, but it also visible on the lower corners as well.
This happens when the phone becomes hot after working for sometime. If I leave it locked and idle for sometime, that image fades away and everything becomes normal. But if I start using the phone again for sometime, the problem comes back.
I kind of think this is something wrong with the lcd panel because if I take a screenshot (of the homescreen/recent apps menu when the problem persists) and view it through the PC it looks fine.
I've flashed both lineage OS and xiaomi.eu ROMs and this happens in both of them.
My phone has a LGD panel.
If anyone here has previously encountered this problem or if anybody have any idea about why this is happening and/or whether there are any solutions for this, I would really appreciate your help

I think its called a screen burn issue. Dont have a solution though
Sent from my MI 5 using Tapatalk

SilverMarcs said:
I think its called a screen burn issue. Dont have a solution though
Sent from my MI 5 using Tapatalk
Click to expand...
Click to collapse
right ... I suspected something like this coz it happens only when the phone is hot. I didn't knew the correct term for that ....
thanks for the reply buddy. appreciate it

It's image retention. Which happen quite frequently on ips display made by LG. Many LG's flagship also suffer this symptom. The only way you can reduce it is by reducing the amount of RGB(Red green blue) colour profile by 5-7% though only doable in LOS.

theVANGUARD Official said:
hello to all,
So I've recently noticed this happening on my mi5 32GB variant. Whenever I close an app, after using it for sometime, a diminished part of that app remain even after closing it.
for example, if I use FB app for sometime and when I close it and go to homescreen, near the upper part of the screen I can see the diminished part of the FB app ( the upper part of FB app) even after closing it.
This can be viewed better if I go to recent apps screen. Since it has a greyish background the image can be viewed better. This is more prominent in the upper corners of the screen, but it also visible on the lower corners as well.
This happens when the phone becomes hot after working for sometime. If I leave it locked and idle for sometime, that image fades away and everything becomes normal. But if I start using the phone again for sometime, the problem comes back.
I kind of think this is something wrong with the lcd panel because if I take a screenshot (of the homescreen/recent apps menu when the problem persists) and view it through the PC it looks fine.
I've flashed both lineage OS and xiaomi.eu ROMs and this happens in both of them.
My phone has a LGD panel.
If anyone here has previously encountered this problem or if anybody have any idea about why this is happening and/or whether there are any solutions for this, I would really appreciate your help
Click to expand...
Click to collapse
Look under display calibration and change your RGB values accordingly: R: 93% G:93% B93% . It works like a charm :highfive: I use LineageOS although not all ROMs have this feature.

Mr.201 said:
It's image retention. Which happen quite frequently on ips display made by LG. Many LG's flagship also suffer this symptom. The only way you can reduce it is by reducing the amount of RGB(Red green blue) colour profile by 5-7% though only doable in LOS.
Click to expand...
Click to collapse
xdadevet said:
Look under display calibration and change your RGB values accordingly: R: 93% G:93% B93% . It works like a charm :highfive: I use LineageOS although not all ROMs have this feature.
Click to expand...
Click to collapse
thank you both for the help :good:
I flashed the LOS latest build and adjusted the RGB according to what you've said. Let's hope it does the trick. :victory:

theVANGUARD Official said:
thank you both for the help :good:
I flashed the LOS latest build and adjusted the RGB according to what you've said. Let's hope it does the trick. :victory:
Click to expand...
Click to collapse
yeah use the LOS 14.1 and adjust the RGB to 90. I suppose it hides the retention effect. To fix the problem completely, I think the only option is the replace the screen.
some people are using KCAL which essentially provides the same options( and more) but keep in mind that it needs root access and kernel modifications.

display brightness

Greetings,
Just received a used device and noticed my unit won't physically lower in brightness at around 25 percent. What I mean is that at around the 25 percent mark, I am unable to perceive it getting any lower when set at a lower percentage. I've also noticed that when I have the brightness at a high percentage and then quickly lower it to the minimum, that the display will at first be quite dim then will suddenly raise itself to a slightly brighter minimum. I do not have auto brightness on, nor any filter apps active while testing. Just wondering if this issue is isolated to my device. Thank you for reading my concern. If anything is unclear, I could try taking a video of the issues. Anyone else with these issues? I've searched the web to no avail.

i just bought a used device as well and mine has the same issues. the backlight seems to flicker on the second screen at low brightness and below about half the second screen is noticably dimmer. its unfortunate that they didn't put a lot of effort into the screen software or quality considering its the main gimmick of this phone, but it is made by ZTE after all. the price you probably paid for one of these things is a lot more representative of the quality than the original MSRP. But its still a fun gimmick even with all the flaws.

stevegalaxius said:
i just bought a used device as well and mine has the same issues. the backlight seems to flicker on the second screen at low brightness and below about half the second screen is noticably dimmer. its unfortunate that they didn't put a lot of effort into the screen software or quality considering its the main gimmick of this phone, but it is made by ZTE after all. the price you probably paid for one of these things is a lot more representative of the quality than the original MSRP. But its still a fun gimmick even with all the flaws.
Click to expand...
Click to collapse
Thanks for your thoughts and input. Yeah this is quite unfortunate on how the phone turned out. I also see the flicker on the second display. But as you mentioned, the device is indeed quite fun. I'm actually thoroughly enjoying the device especially with books and comics reading in the extended mode. I tend to do some late night reading, so that was the reason why I brought up the display issue as I had wanted to get the display as dim as possible before applying a filter. Hopefully one day we'll get root to check out if we can lower the display minimum brightness level along with other lower level system modifications.

axxtran said:
Thanks for your thoughts and input. Yeah this is quite unfortunate on how the phone turned out. I also see the flicker on the second display. But as you mentioned, the device is indeed quite fun. I'm actually thoroughly enjoying the device especially with books and comics reading in the extended mode. I tend to do some late night reading, so that was the reason why I brought up the display issue as I had wanted to get the display as dim as possible before applying a filter. Hopefully one day we'll get root to check out if we can lower the display minimum brightness level along with other lower level system modifications.
Click to expand...
Click to collapse
apparently a few weeks ago someone released TWRP for this device. its not quite a root but it still gives you root access to change the build.prop and some low level system settings. TWRP is the sign that there is some kind of development happening but i wouldn't hedge your bets on anybody fixing the screen issues even with some kind of kernel modification

stevegalaxius said:
apparently a few weeks ago someone released TWRP for this device. its not quite a root but it still gives you root access to change the build.prop and some low level system settings. TWRP is the sign that there is some kind of development happening but i wouldn't hedge your bets on anybody fixing the screen issues even with some kind of kernel modification
Click to expand...
Click to collapse
That is definitely a most welcome update. I'm curious on what build your device is on since you mentioned having similar issues to mine. I am on b30 myself and will be flashing to b37 when I get a chance to see if there are any differences.

Weird glitch when phone is in dark mode (colour shifting when taping display)

Hi everyone,
Got my Pixel 4 XL on the 23rd and been playing around with it since then. I am now settling into a rhythm and noticed a very concerning glitch with the display when the phone is in dark mode. Basically, when the phone is in dark mode I noticed that typing in Gboard or tapping anywhere on screen in apps that are not pure black (such as Messages, Phone, etc.) will shift the screen colour from blueish-black to greenish-black. This happens every time, even after rebooting the device. There is no visible colour shifting in apps that use pure-black such as Settings (however, parts of Settings like the search bar that are the "gray" dark colour also shift). Once I noticed this happening now I cannot stop noticing it everywhere. I am looking to find out from you whether you are seeing the same thing or whether this may be a device problem. Note that the same issue shows up in dark apps even if dark mode is not enabled. It also has nothing to do with Ambient EQ, Automatic Brightness, or anything else of similar nature. Occasionally the problem stops, but if I pull up Gboard and start typing (say to search in the Recent section of the phone app) the problem immediately comes back.
I am looking for serious feedback here from those willing to look closely. This does seem like a software glitch to me, rather than hardware, especially since I am not seeing this behaviour with any other colours and so far it definitely has something to do with physical interaction with the screen when tapping on it. As I said, it also seems to be universally triggered by Gboard when in apps running in dark mode.
I appreciate any feedback you can provide.
Edit: Looks like what I'm observing is related to the switching colour profiles when the display is going back and forth between 60Hz and 90Hz. Turning off the smooth display function or forcing the display into permanent 90Hz mode appears to stop the problem from happening. Google really messed this one up. I hope their 90Hz fix they promised clears up this issue. Very annoyed ?
Thanks,
Dejan

Btw, since you are using forced 90hz display make sure to have always on display on. If you don't your greys will be purple and lower brightness as well as lots of black smear/crush. I don't know how turning on always on display solved that issue (someone posted this fix in another thread). So it indeed doesn't seem to be hardware but software related and hopefully they will tune this over time.

zetsumeikuro said:
Btw, since you are using forced 90hz display make sure to have always on display on. If you don't your greys will be purple and lower brightness as well as lots of black smear/crush. I don't know how turning on always on display solved that issue (someone posted this fix in another thread). So it indeed doesn't seem to be hardware but software related and hopefully they will tune this over time.
Click to expand...
Click to collapse
Yeah, I saw that thread. Some funky stuff going on with display calibration and 90Hz. Since I know that the HW is not defective and the SW is the source of the issue I am less bothered now (I cannot stand exchanging HW). I haven't specifically observed that effect on my phone and while I did try forcing 90Hz, I actually went back to the stock setting since I noticed that forced 90Hz further sucked down the battery that already is not particularly stellar despite this being the XL version. I presume Google will refine the 90Hz calibration and function over the next few months. I will say though that I am a bit confused why they need to have different calibration at different refresh rates. I calibrate all of my desktop monitors and despite the fact that I have a 100Hz monitor I never have to change calibration with refresh rate. Maybe an OLED thing :shrug:

dhorgas said:
Hi everyone,
Got my Pixel 4 XL on the 23rd and been playing around with it since then. I am now settling into a rhythm and noticed a very concerning glitch with the display when the phone is in dark mode. Basically, when the phone is in dark mode I noticed that typing in Gboard or tapping anywhere on screen in apps that are not pure black (such as Messages, Phone, etc.) will shift the screen colour from blueish-black to greenish-black. This happens every time, even after rebooting the device. There is no visible colour shifting in apps that use pure-black such as Settings (however, parts of Settings like the search bar that are the "gray" dark colour also shift). Once I noticed this happening now I cannot stop noticing it everywhere. I am looking to find out from you whether you are seeing the same thing or whether this may be a device problem. Note that the same issue shows up in dark apps even if dark mode is not enabled. It also has nothing to do with Ambient EQ, Automatic Brightness, or anything else of similar nature. Occasionally the problem stops, but if I pull up Gboard and start typing (say to search in the Recent section of the phone app) the problem immediately comes back.
I am looking for serious feedback here from those willing to look closely. This does seem like a software glitch to me, rather than hardware, especially since I am not seeing this behaviour with any other colours and so far it definitely has something to do with physical interaction with the screen when tapping on it. As I said, it also seems to be universally triggered by Gboard when in apps running in dark mode.
I appreciate any feedback you can provide.
Edit: Looks like what I'm observing is related to the switching colour profiles when the display is going back and forth between 60Hz and 90Hz. Turning off the smooth display function or forcing the display into permanent 90Hz mode appears to stop the problem from happening. Google really messed this one up. I hope their 90Hz fix they promised clears up this issue. Very annoyed ?
Thanks,
Dejan
Click to expand...
Click to collapse
I just noticed this on my pixel 4 xl tonight. But It only happens when the proximity sensor is triggered. Ex: like after making a phone call except it made everything on the screen seem over saturated on the screen and well as the same color shift you had stated. It seems to go away once I lock the device and unlock it again. It did it with smooth display on and off as well as force 90hz on and off.

There are a couple threads discussing this. Here's one of them:
https://forum.xda-developers.com/pixel-4-xl/how-to/smooth-display-colour-issues-t4000087
And another:
https://forum.xda-developers.com/showthread.php?t=3998907
Sent from my Pixel 4 XL using Tapatalk

Question Realme GT 2 problem with AMOLED display and text visualization

Hi, I recently bought a Realme GT 2 8/128GB Global RMX3311_11_A.14 firm and have been using it for past couple of days.
What I have noticed like artifacts around black text on white background, like a bright halo under dark shapes and clear/light background, it's like a 1px brighter-than-the-background, like a broken anti-aliasing/ClearType or maybe is that the sharpness is very high.
I have tried all the configuration options available for the screen but there have been no changes. For example, in the list of Wi-Fi networks, in the password field, if you look at the black line, it is in one of the places where it is most noticeable.
https://imgur.com/t50LOm5
it is very difficult to capture with a camera, this is not my phone but the same thing happens
https://imgur.com/zOkyWWG
I think i have same problem which is reported in this other thread for a Xiaomi phone https://forum.xda-developers.com/t/over-sharpened-mi-11x-amoled-display.4319715/
Is this normal or there's any problem with my display? Is this a Realme UI 3 issue and can be solved in following updates?
I have other three Amoled phones and this DOES NOT happen to any of them! (Realme 8, Oneplus 3T, Xiaomi Mi A3)
thanks!
regards

Do you have DC Dimming enabled ?
I noticed that when it is enabled in low brightness and black background there's some flickering on the page text when scrolling.
But that particular issue I don't have.

Hi apsol, thanks for your answer
No, I did not have DC dimming active, I have tried to activate it but it has no effect on what I comment
with time I'll get used to it, now I know it's there and I see it. What I would like to know is if it is a problem with this AMOLED panel or rom/driver issue which could be adjusted via software

I know how it is, once you see it you can't unseen, it would drive me nuts too. Hehe
Have you tried testing for dead/stuck pixels if it doesn't show there my guess is software.
I'm on RMX3311_11_A.14.
What about you ?

Hi,
Same firmware version here, RMX3311_11_A.14 global
the truth is that I am not sure if it also happened with the A.13 because I almost updated it at the moment, I did not realize this until I was in the A.14 ...
thanks

The same problem on my phone. It is easier to see also on black background with white font.
Unfortunately I think this is a screen issue not soft

Have anyone have similar issue? Is this global problem or only 2 of us struggle with this issue?

Check if you have high contrast text enabled.

I have high contrast disable ( but the same issue is visible when option is on). Do you have this is issue? Or should I send my phone on RMA?

I don't.
If it bothers you that much return it.

Hi again,
After continuing to search for information on this issue, I found following post on reddit that I think has the same problem with an iPhone 13
https://www.reddit.com/r/iphonehelp/comments/tdy5tc
I think it's a common problem with AMOLED screens, but in some it is more noticeable than in others and it also depends on the user
after detecting it on my Realme GT 2, if I make an effort, perhaps I could say that it also happens on my OnePlus 3T, however the difference with my Realme is remarkable, the same with a Realme 8 of a family member
By the way, another thing that I have detected is a color shifting when the viewing angle is varied, much higher than in my other devices with AMOLED, it must be said that the larger the screen, the more noticeable it is
I'm a little disappointed with the screen to be honest
thanks

MrAnon said:
Hi again,
After continuing to search for information on this issue, I found following post on reddit that I think has the same problem with an iPhone 13
https://www.reddit.com/r/iphonehelp/comments/tdy5tc
I think it's a common problem with AMOLED screens, but in some it is more noticeable than in others and it also depends on the user
after detecting it on my Realme GT 2, if I make an effort, perhaps I could say that it also happens on my OnePlus 3T, however the difference with my Realme is remarkable, the same with a Realme 8 of a family member
By the way, another thing that I have detected is a color shifting when the viewing angle is varied, much higher than in my other devices with AMOLED, it must be said that the larger the screen, the more noticeable it is
I'm a little disappointed with the screen to be honest
thanks
Click to expand...
Click to collapse
I came specifically to this forum to check whether its true about the screen's colour shift and font edge issues. Seems its true. Its believed that they have used the same samsung E4 hard screen, that they used in oneplus 9RT. You can check 9RT's display review below:
https://www.gizmochina.com/2021/10/22/oneplus-9rt-review-perfect-balance-camera-price/
There is also a Chinese video on GT2 display. Its a review of k50 and gt neo3, but they have shown display of gt2 also. Watch from 2:30 min.

I don't see that problem on my gt2 in normal use.

I also have the blue shifting even when looking straight. I try to ignore it.
Someone told me it was the screen protector but I never removed it to be sure.
But every review I've seen there is color shifting.