Develop Bugs

Screen quality

How do I check to see if my screen is a not so good one I see the lines sometimes when the screen is off they are purplish is that what everyone is talking about?
Also my GS2 seems to be not as bright as my Exhibit 2 any idea why shouldn't these phones be really bright and stand out?
maybe I got a bad screen.
any help would be appreciated.

yes this is what lots of people complain about. I have had 4 phones with this issue, 3x black and one white. I have one that was listed as a march 2012 batch and it has even worse issues then the one I exchanged it for.
IMHO there really needs to be a class action lawsuit aginst samsung for these defective units.

1 our gs2 well the first couple thousand have a, line blob issue
and
2 have you check off auto sceen power
Sent from my SGH-T989 using XDA

don728871 said:
1 our gs2 well the first couple thousand have a, line blob issue
and
2 have you check off auto sceen power
Sent from my SGH-T989 using XDA
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what? do you mean I need to turn off auto brightness?

PlatinumMOTO said:
what? do you mean I need to turn off auto brightness?
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No further down in display settings....uncheck that....also I have brightness on full blast...auto brightness defeats the purpose of our screen it really does. I still get great battery life

A thread about this has already been addressed over here http://forum.xda-developers.com/showthread.php?t=1320942
I'm just sayin!

[Q] Screen flickering (CRT like)

Hi,
EDIT
Resolved it (kinda), I shut the "Economy mode" and the screen stop the flickering....
---
I'm creating a new thread for this problem got an answer there telling me it's my phone, but I would like to know if somebody else notice this.
It's like on good old CRT. Got a Note I (got stolen) bought a Note 2 and I can see a flickering, like if the display had a 60Hz refresh rate, never notice such a thing with the Note I.
It's more noticeable on white screens. And when you are using peripheral vision, by pointing your eyes like 10 centimeters from the side of the device, the flickering must be more visible
The effect looks like this http://www.youtube.com/watch?v=M3jHOwE8MqA not mine but can give an idea of the problem.
Thanks

Livebyte said:
YES I HAVE SUCH A PROBLEM.
I was worried sick that my phone might be going dead soon.
And I'm talking about Note 1 here.
I don't want to waste money on a Note 2. I don't want burn my wallet again! ):
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Never notice it with my Note I, it seems that it's partly due to AMOLED technology, but as I did not notice it on my Note I...
Maybe it varies form device to device...
The effect looks like this http://www.youtube.com/watch?v=M3jHOwE8MqA

Livebyte said:
YES I HAVE SUCH A PROBLEM.
I was worried sick that my phone might be going dead soon.
And I'm talking about Note 1 here.
I don't want to waste money on a Note 2. I don't want burn my wallet again! ):
Click to expand...
Click to collapse
It's Float like a butterfly, sting like a bee.

Livebyte said:
Yes I have it, but mine is definitely more severe than yours.
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Then why didn't you return it under warranty?

Go to Display > Features > Smart Rotation . Disable Smart rotation and voila the problem is resolved....

BoneXDA said:
It's Float like a butterfly, sting like a bee.
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Click to collapse
Don't feed the troll

Ok, so if you do not own this device the Note 2, and do not want the device, why chime in and post/comments...

My scraan is flickering too. Feels like old CRT TV. When brightness not at 100% level I can observe this problem. Looks like samsung using PWM to control brightness. I think this is terrible. And I hope this can be fixed by software (adjust brightness by gamma correction etc)

mine also sometimes flickering on the lock screen in the near clock area for about 0,5-1 sec. but no need to worry, i guess its a hidden samsung note 2 feature...

So there are no solutions to fix screen flickering? Maybe we can overclock screen somehow? Maybe alternative brightness control?

The screen flicker mus be due to a bad batch of screens. Mine had the screen flickering too. and even with economy mode shut down and brightness is set to less then 100%. if you rapidly move the phone you can see that you see several screens instead of a blurry moving screen. this way you know it flickers. so for example if you move your phone up and down very rapidly instead of seeing a blurry view of the screen you will see several edges of the screen simultaniously. this tells you its flickering. While just looking at the screen you wont actually see the flickering but its somehow disturbing.
The way i know that your screen is defect is because due to a rescent replacement of my screen on my note 2 the flickering is totally gone now.
But keep in mind that my battery usages with screen on has increased. so i think samsung changed the power management for these new screens so that they wont flicker anymore. but they consume more power now. first i used the screen 6,5 hours and had a standby of 24 hours. now i have 6 hours screen on time with 24 hours standby. so its a bit of a change though. I just tested it 1 time. so it could also be i used the phone in another way when getting only 6 hours.
But just to let you guys know the flickering can be fixed.

[Q] Why is the refresh rate on the Note 2 58hz?

Hello folks,
I have had my Note 2 for a couple of days now and almost immediately noticed something strange. There is a VERY subtle flickering of the white and light grey areas of the screen. A very high frequency flicker, almost like I can see the refresh rate of the screen. My initial suspicion was that the refresh rate was lower than 60hz. So, I downloaded the app called Android System Info, and sure enough, under display, it was being reported that the refresh rate of the screen is 58hz. I got another friend with a Note 2 to confirm the same thing. My GS3 reports 60hz, and so does my friends HTC One S. So my question is, why is the refresh rate on the Note 2 not 60hz? Is this an intrinsic hardware limitation? Or can this be changed with software? My eyes can definitely notice the 2 less frames per second, I was using a GS3 since June, and switching to the Note, I immediately noticed the refresh rate was lower. Why? This is very strange to me. There are many videos on YouTube with the Note 2 and GS3 on the screen at the same time, and sometimes there is banding interference on one phone and not the other, meaning obviously the phones are running different refresh rates. Now I know the Note 2 refresh rate is lower, why? And is there anyway to change it with software?
Thanks much!

first, i think u should get yr note2 to warranty,
second, u sure yr eyes can differentiate 58hz and 60hz......?

emprize said:
first, i think u should get yr note2 to warranty,
second, u sure yr eyes can differentiate 58hz and 60hz......?
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It is EXTREMELY subtle, almost a non issue, so I doubt warranty will even say anything is wrong. I can notice it on all the demo models i've seen, so I doubt it has anything to do with my phone.
I have confirmed on 3 different Note 2s, the reported refresh rate in the app 'Android System Info' is 58hz. While all other phones I have used report 60hz.
I just find this so strange that maybe someone has a great explanation as to why this is the case. And maybe someone can dig deeper than I can and figure out if this is in the OS or an intrinsically hardware thing. I wish I had the email of a Samsung engineer who worked on the design of this phone, would love their take on why this is the case. 58hz is just such a strange refresh rate.

Goontron said:
It is EXTREMELY subtle, almost a non issue, so I doubt warranty will even say anything is wrong. I can notice it on all the demo models i've seen, so I doubt it has anything to do with my phone.
I have confirmed on 3 different Note 2s, the reported refresh rate in the app 'Android System Info' is 58hz. While all other phones I have used report 60hz.
I just find this so strange that maybe someone has a great explanation as to why this is the case. And maybe someone can dig deeper than I can and figure out if this is in the OS or an intrinsically hardware thing. I wish I had the email of a Samsung engineer who worked on the design of this phone, would love their take on why this is the case. 58hz is just such a strange refresh rate.
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you are the man, mate, my eyes cant even differentiate 50 and 60 Hz, for all my note2 experience, i cant see any unusual on the screen.
But for the 58hz issue, i think its not quite a strange thing for me, it reminds me when i was using CRT monitor(or early lcd?), it always can set the refresh rate to 58hz or 60hz, but it might like u say a hardware or driver problem, hope u can contact with samsung engineer and tell us the answer

I suppose the app might be reading the values of somewhere not actually measuring it or something ! Correct me if am wrong .

this is interesting. i also notice a subtle flicker of the screen. it's annoying in some lighting. i don't notice it on other phones.. it's definitely seems like the refresh rate is a bit slower than it should be.

The refresh rate is correlated with the resolution and the main base clock which feeds the display controller, in this case 1280 * 720 * 58Hz = ~54Mhz plus some margins for which are too long to describe, which gives them a target frequency of about 54MHz for a 16 divider of the 880MHz base clock. That's the main reason of the 58 vs 60 Hz difference.
But the reason you're seeing flickering might be completely unrelated to that and caused by some odd much lower timings in the display settings. Maybe a developer with the device could test it out by changing them.

AndreiLux said:
The refresh rate is correlated with the resolution and the main base clock which feeds the display controller, in this case 1280 * 720 * 58Hz = ~54Mhz plus some margins for which are too long to describe, which gives them a target frequency of about 54MHz for a 16 divider of the 880MHz base clock. That's the main reason of the 58 vs 60 Hz difference.
But the reason you're seeing flickering might be completely unrelated to that and caused by some odd much lower timings in the display settings. Maybe a developer with the device could test it out by changing them.
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Click to collapse
Thanks for that information, it's great technical info I've been looking for. So it's basically a ratio/multiplier of some clock speed in the hardware. But now my question is, why would the Note 2 be any different than a GS3? I would think they have relatively the same hardware, and resolution on both screens is the same, so why would the refresh rates differ? Just seems to me that 58hz is not an ideal refresh rate. I mean, the main reason there is a trend towards 120hz TVs these days is because both movies (24 fps) and TV (30 fps) are evenly divisible into 120. Whereas with a 60hz TV, there is a remainder on 24, so movies do not interpolate as smoothly. With 58hz, no recorded content I can think of divides evenly into it, always making interpolation less smooth. Again, in my mind, 58hz is just silly, why not just give me the extra 2hz!! Doesn't make sense to me.
Final question. Would there be any way with software to change the refresh rate? Or is this set in stone at the hardware level?

I have an issue with this as well - I'm getting either fairly heavy frame skipping in any 8 or 16 bit emulator with frame skipping set to auto, or sound skipping with frame skipping turned off. I suspect this is because of the odd refresh rate with the app expecting 60hz and only running at 58 in reality, causing either the video or audio to run out of sync and needing to skip the two frames here and there to catch up. If the emulators could slow down the audio speed to match the slower video speed, it wouldn't be an issue.... but this shouldn't be the problem of the emu authors.
This happens with no other applications installed on a brand new phone. I've also installed clean rom and perseus kernel, no change. Power settings are all off, nothing is hitting my CPU to cause the frameskipping and it's very consistent, which leans towards the refresh rate causing the issues. Anyone know anything more about this? What a pain...

I am a traffic cop and I can definitely tell the difference between a car going 58mph and one going 60mph.
Sent from my GT-N7100

@rbiter said:
I am a traffic cop and I can definitely tell the difference between a car going 58mph and one going 60mph.
Sent from my GT-N7100
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I'm a noob and I don't know what "stuttering" is
But seriously, it's not like a mobile device should be able to emulate another system anyway, am i rite? Just use it for phone calls and internet browsing...

i think the reason why the refresh rate between gs3 and note2 is different due to both are using different lcd even though some of the hardware is the same.
even though the diff is small but it still incur some major hiccup where the frame skip especially with project butter where they keep the ui at 60fps.
maybe we can email to samsung engineer and they can take a look at it.

HTC 10 screen flickering (PWM)?

Hi all!
Does anybody know if HTC 10 uses PWM (Pulse-width modulation) for brightness control?
PWM is a cheap and easy technology to manage screen brightness. To adjust brightness PWM-controller rapidly (usually with speed of 230-240 Hz) turns backlight on and off, which in turn could cause headaches and eye fatigue after using the device.
More about PWM: https://en.wikipedia.org/wiki/Pulse-width_modulation
Absence of PWM is one of the key parameters for me. Unfortunately only a few reviewers test flickering and this information is very hard to find. So far, I have not found a single review with PWM test.
Thank you!
21.05.2016 update: Notebookcheck confirmed that HTC 10 is flicker free!

Surely the only way to dim LEDs is with PWM?

Nope, PWM is just the cheapest an the easiest way. Plus controller won't overheat.
But there are other ways to dim LEDs. One of the oldest ways - variable resistor.

Considering humans see appx 60-90 hz I'd say this is a non-concern.
Unless you're a mutant who can see 100hz+ in which case you must go crazy anywhere you go from the constant exposure to higher frequencies.
Sent from my HTC One using Tapatalk

Considering that I had 5 laser eye surgeries this concerns me a lot.
Using a screen with PWM for more that 15 minutes causes eye strain for me. And this is the main reason why I haven't already bought Galaxy S7.
You are lucky that PWM doesn't affect your eye, and probably should google further more: https://www.google.ru/?#safe=off&q=pwm+eye+strain

datafoo said:
Considering humans see appx 60-90 hz I'd say this is a non-concern.
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Where did you get that info? Especially flickering can be seen at even higher frequencies. I personally see flickering on the XPS 15 and it uses PWM at around 362 Hz.
http://www.notebookcheck.net/Dell-XPS-15-2016-9550-InfinityEdge-Notebook-Review.156354.0.html
It's not disturbing but it is noticeable.
http://www.100fps.com/how_many_frames_can_humans_see.htm
Also the difference between 60 Hz and 144 Hz in a monitor is obvious just by dragging windows around.
If you can't see it, fine. But don't go around telling untrue stuff please.

Dr. lele said:
Where did you get that info? Especially flickering can be seen at even higher frequencies. I personally see flickering on the XPS 15 and it uses PWM at around 362 Hz.
http://www.notebookcheck.net/Dell-XPS-15-2016-9550-InfinityEdge-Notebook-Review.156354.0.html
It's not disturbing but it is noticeable.
http://www.100fps.com/how_many_frames_can_humans_see.htm
Also the difference between 60 Hz and 144 Hz in a monitor is obvious just by dragging windows around.
If you can't see it, fine. But don't go around telling untrue stuff please.
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Untrue stuff LOLOLOLOLOL - I believe you're suffering a nocebo effect.
Pardon my incredulity but as I mentioned if you see anything over 100hz you're a mutant (I said 60-90hz) and that appears to be corroborated by your 100fps link. I'm not completely disagreeing with you, I'm however pointing out that you're such a small subset of the population it's rare and hard to validate.
Although FPS and HZ are different we'll bypass the semantics for the fact we're discussing cycles per second in a general fashion.
It must drive you crazy being ANYWHERE with lighting and electricity. At least here in the US electricity runs at appx 60hz so lights (most computer monitors etc) must bother you quite a bit.
Either way, good luck to you. I hope you find what you're looking for.

There is of course a difference between the way LCDs refresh their content and the way CRTs did. Strobing of light can definitely be seen at much higher rates than you said.
Also I never said that it's infuriating or drives me crazy I just said it's noticeable. I have no idea where you get this from.
Tests with Air force pilots have shown, that they could identify the plane on a flashed picture that was flashed only for 1/220th of a second.
That is identifying. So it's pretty safe to say, that recognizing, that SOME light was there is possible with 1/300th of a second.
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That was the part I wanted to show you.
Now the blur on LCDs is a different story, since the lights are on constantly and only the pixels change color at the given rate. But still you cann see the motion blur / dragging of the cursor even on a 144 Hz screen. Albeit much less noticeable than on a 60 Hz one.
If given a 60 Hz display side by side with a 144 Hz panel most people will be able to tell you which one feels more natural.
BTT: I don' think it will be a real poblem even if HTC does use a PWM module. Even though it might be somehow noticeable it won't disturb most people. Also: how often do you use your phone at the lowet brightness.

Yay! HTC 10 is PWM (flicker) free! Confirmed by Notebookcheck: http://www.notebookcheck.com/Test-HTC-10-Smartphone.164311.0.html (in German).
Oscillogram: http://www.notebookcheck.com/fileadmin/Notebooks/HTC/10/response_pwm.jpg

Just want to add that being able to notice it and it affecting you are two different things. Normally you can't notice neon lights flicker but they do and it will strain your eyes and make you tired. That's why bars have started to charge them out to leds.
Sent from my HTC 10

Glad I'm not effected by this crap. I'd hate having to pass on phones I really like just because they use PWM.
Sent from my SM-G935T using Tapatalk

VERY weird scan lines on low light

Hey guys. So I was at a restaurant earlier this evening and I was about to take some pics with my 5t when I noticed something really weird. Black vertical lines zooming from side to side on the image. The lighting was relatively dim and I noticed it stops when I focused on a white plate.
I tried with different camera apps and it kept happening. I took some videos to show you guys. I'm really hoping this is not a hardware issue because I'd hate to send the phone back.
Have any of you had these issues? Any thoughts?
Here are the videos:
And this one shows it happens with photos as well:
HALP

that ain't no issue. that's common on any camera.
It is the refresh rate of the screen and the lights not matching up. TV in the UK is broadcast at 24 fps, so lighting in the UK is tailored to match at 24hz.
you'll see those lines on poor light/LEDs on preview mode only. some camera apps have the option to change the hz from US to UK.

Abaddon said:
that ain't no issue. that's common on any camera.
It is the refresh rate of the screen and the lights not matching up. TV in the UK is broadcast at 24 fps, so lighting in the UK is tailored to match at 24hz.
you'll see those lines on poor light/LEDs on preview mode only. some camera apps have the option to change the hz from US to UK.
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I had no idea lighting could mess with the refresh rate of a camera. It's weird because the problem is not only on videos. When I snap a picture the lines are there also. Is that because of the refresh rate too? On a still image?

I too have the same problem

Abaddon said:
TV in the UK is broadcast at 24 fps, so lighting in the UK is tailored to match at 24hz.
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Excuse me but no. Standard TV is 50Hz, and I bet at least some HD channels transmit in 50Hz. Regardless of this the AC switching rate is 50Hz. Unless you're talking of another UK (I was referring to the one with the Queen).

Is this an isolated case or is it another oneplus problem like oneplus 5?

OrtizFerrari said:
Is this an isolated case or is it another oneplus problem like oneplus 5?
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It's not a problem at all... It's how cameras pick up certain lights since they refresh at different rates. Try recording a tv or computer screen. You'll likely see it flickering the same way.

mazdamiata210 said:
It's not a problem at all... It's how cameras pick up certain lights since they refresh at different rates. Try recording a tv or computer screen. You'll likely see it flickering the same way.
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Yes I know that differents frecuences could make interferences, but I bought the phone after a bad experience with the Oneplus 5 jelly and I'm worried haha Great to read that, thanks!

Just wanted to confirm that there's no issue. Tested with a Oneplus One and a Samsung Galaxy S5 camera. Both had the same effect under that lighting. I guess I learned something new.

Ok, could one moderator close this thread? Because someone can think that this is an issue of the phone...Anyway, I like to see that you've learned something new @Lord Zafakon