i9505 | Red subpixels on while displaying black **PROBLEM** - Galaxy S 4 Q&A, Help & Troubleshooting

So, several people have reported this issue.
While booting, the black is actual BLACK. While charging, the black [not the green/grey battery] is actually BLACK.
When you reach the Samsung animation in the booting process, the areas of the screen previously black get a reddish tint.
On closer inspection, all red subpixels are on, at low intensity. As far as I can see brightness setting does not affect this phenomenon, nor does Display Mode.
i9505 On XXUAMDF:
Comparison, white image, lowest brightness:
Can people report their firmware and model and whether they have this issue? It's mostly visible in pitch black rooms, but you can tell the blackness isn't OLED-black in normal situations. It's obviously a big issue as it will also drain additional power compared to pixels that are off.

Related

darker and brighter stripes on gray background

i have this problem(maybe common in amoled devices) if i take gray pitchure and put it on background there is distorsion in grey. like brighter and darker stripes(but you need to look it realy good) for exsample download program screen helper lite and tell me do you see stripes on main gray program screen.
There is a thread going for so long,
http://forum.xda-developers.com/showthread.php?t=1079444
Regards.
I think that he meant this:
http://forum.xda-developers.com/showthread.php?t=1075364&highlight=banding
http://forum.xda-developers.com/showthread.php?t=1121840&highlight=banding
I dont think he is refering to both yellowish screens or banding.
I'm having this issue too. It doesnt show itself unless the screen brightness is turned down, and especially an grey background. There will be faint large vertical stripes. It is as if the backlighting is uneven. Increase the brightness and it'll go away.
Seeing that i do not have the yellowish screen problem, no stuck/dead pixels and no bluish tint problem, im very reluctant to send this phone back for a replacement due to this problem. Its something that i can live with.

An issue I never understood (Ultra power saving mode)

Hi there !
Just call me a noob - but I don't understand a feature of that "Ultra power saving mode". It's the black and white display.
If we dare to ignore the special features of a pentile matrix, it comes down to a pixel consisting of three subpixels: Red, Green, Blue (RGB).
To display greyscales of the color "white" , we need ALL THREE subpixels illuminated: [•••]
For displaying the colors "red", "green" or "blue" we'd need just ONE subpixel illuminated: [•] or [•] or [•]
Clear so far ? - Well.
AMOLED displays control each subpixel directly - many subpixels illuminated = high energy drain, few subpixels illuminated = low energy drain.
So is there any sound reason for choosing a display color (grey) which always needs ALL subpixels illuminated, thus causing three times the battery drain a red, green or blue display would cause ?
Do I overlook something ?
AMOLED display is just multiple lights producing images. The reason the ultra power saving mode is black and white is because AMOLED display will turn off the light in the subpixels to produce the black color.
Chefproll said:
Hi there !
Just call me a noob - but I don't understand a feature of that "Ultra power saving mode". It's the black and white display.
If we dare to ignore the special features of a pentile matrix, it comes down to a pixel consisting of three subpixels: Red, Green, Blue (RGB).
To display greyscales of the color "white" , we need ALL THREE subpixels illuminated: [•••]
For displaying the colors "red", "green" or "blue" we'd need just ONE subpixel illuminated: [•] or [•] or [•]
Clear so far ? - Well.
AMOLED displays control each subpixel directly - many subpixels illuminated = high energy drain, few subpixels illuminated = low energy drain.
So is there any sound reason for choosing a display color (grey) which always needs ALL subpixels illuminated, thus causing three times the battery drain a red, green or blue display would cause ?
Do I overlook something ?
Click to expand...
Click to collapse
U r right ...
So... Instead of white pixel there should be one of 3 main colors ( red blue green ) in order to minimize the power consumption .
Using white pixel makes no sense for AMOLED displays ...
does having a red blue or green tinted display make any sense to you ? that is why.
Found this information, maybe it is useful:
An AMOLED doesn't have a backlight at all.
Instead, each little sub-pixel is like a tiny red, blue, or green colored light.
If the screen is instructed to display black, it doesn't need to block any light, it simply doesn't light up any of the little colored sub-pixels.
So theoretically, black pixels save you a lot of power because those pixels can be turned completely off.
However, people sometimes make the mistake of thinking this is a function of brightness—that dark colors like gray are similarly efficient.
Source: http://www.greenbot.com/article/283...interface-really-save-on-amoled-displays.html
Kind regards, Stefan.
zurkx said:
does having a red blue or green tinted display make any sense to you ? that is why.
Click to expand...
Click to collapse
Did you understand the purpose of an energy saving feature ? - I'll tell you. It's for saving energy.
Not for giving you a pretty sight.
Basic information (I thought everybody knew that): AMOLED indeed is like millions of single LEDs. The more illuminate, the more power you need.
Black screen: NO energy consumption. White screen: Highest energy consumption (because white light consists of red, green and blue light). Red, blue or green screen: 1/3 energy consumption, because just one out of each three subpixel LEDs is lit, thus just one out of three subpixel LEDs consumes energy.
So you need ONE LED for displaying a red, blue or green pixel. But you need THREE LEDs for displaying a white or grey pixel, so it's three times the power consumption.
Now again: It's an energy saving feature. With a green, red or blue screen, energy consumption would be 33 %. But with a grey screen, energy consumption is 100 %.
So where's the sense ?
you're incorrectly making the assumption that an active subpixel always draws full power.
if a subpixel is used to display #808080(which should be a very average grey) it should use around 50% of what it uses when used for displaying #FFFFFF(white)
I don't know how power consumption scales compared to brightness, but using multiple subpixels at 25-40% instead of 1 subpixel at 100% would save a lot of power if power consumption scales with an upward curve as brightness increases.
I don't know the exact characteristics of OLEDs or the effect that pentile has on battery usage so I can't exactly tell why it would drain less in B&W than in color, but grey definitely drains less power than white.
1 interesting thing I just found out:
while I've had several OLED devices, the Note 4 is actually the only one I've ever seen that turns off subpixels to display pure black(#000000)
other devices keep subpixels at their lowest active setting, resulting in a faint green/grey glow.(effectively #010101-#101010, as the lowest setting can vary in brightness between different subpixels)
a downside to this is that black causes ghosting, as it takes a subpixel significantly more time to wake up than to increase brightness.
EDIT: I just did some calculations and comparisons, although this example specifically applies to RGB screens you'd notice a similar effect in RGBG screens.
to create the B&W equivalent of a single colored subpixel at 100% brightness you'd need 3 subpixels to be at only 28%.
even if power consumption is linear to brightness it would still mean a drop in display power consumption of 16%
no its for pretending to save energy not to actually save it. it looks like its an eink screen in that mode so people are happy. thats the sense.
Possibly another reason for choosing black and white instead black and green or other colors to have subpixels "age" at similar rate instead one color loosing brightness at faster rate than others.
Sent from my SM-N910T using XDA Free mobile app

color display screen issue.(1st time to use amoled screen)

I just brought a yotaphone 2 and notice the screen (color side) will change to red/purple in color (especially the dark color area , like the black one) when i set the brightness to a low level(below 30%)
is it normal issue to all amoled display??
this is my 1st time to use amoled phone
nope, it could be damaged during transport. check if yellow spots appear, that's usually the sign of damage. nothing to worry about, it's just annoying
It is normal - if you are in dark and you lower brightness less than 20% it gets purple.

S8 Display turning Yellowish and dark lines with <50% brightness

Hi,
I am using S8 SM-G950FD on stock android 8.0.0 from year+, all of a sudden the display on the screen has turned yellowish, i have tried the adaptive display option and changed the RGB to max and low and the settings for edge colour but the display is still yellowish.
Also noticed another thing: If the brightness is <50% the yellowtinge with black lines come up but if >50% then the display is fine.
I tried to click photos/ take screen shots but the yellowish is not visible on photo, but the dark horizontal lines on whitebackground are clearly visible. have not dropped the phone but this has begun suddenly.
when the phone is under bright light the automatic brightness increases the brightness of screen and the display is clear, when the phone is moved into low brightness the mentioned issue comes up
Any suggestions on how can i resolve this?
Any help is appreciated, phone is out of warranty. Is there any any replacement circular for galaxy s devices, like FOC?

Gradient in brightness

Has anyone noticed there is a gradient in brightness on the main display of the LG g8x or is it just me and my phone
The best way to notice this is to open any gray background and look at it in landscape mode
yes, Many of them have same problem but it affect only in night time, day time can't find the issue.i don't know whether gradient, uniformity issue are same but my phone have uniformity issue (dark gray background with 0% brightness) bright in top,dark patches in bottom.so I change screen colour to sport and warm temperature better than before screen (reduce only small part of dark patches in bottom ).use dual screen in dark room change the screen colour you may see the difference or may not .uniformity issue also in LG latest oled tv.

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