[Q] hardware related screen (backlight) flicker problem - Asus Eee Pad Transformer Prime

Hi folks
I have just changed the mainboard from my TF201 with one i bought off ebay (TF201 with badly damaged screen).
Now i have a heavily flickering, dark screen. The flicker goes evenly over the whole image, that turns on and off, so i assume it's the backlight. The brightness resembles the lowest setting. The screen flicker frequency is dependent on the brightness setting. Lowest Setting: about 4 on-off-cycles per second. Super IPS+ Setting: i would say about 25/second (still a noticable flicker, but the tablet is usable).
When there is just little stuff to draw on the screen (like at the "power down?" message) the flicker becomes even less noticable (ie. faster) while the brightness stays low.
The problem seems to be on the mainboard, because both my screen AND the broken one work just fine on my old board.
On close inspection I found a tiny burnt out IC close to where the WIFI-related circuits are on the board. Please take a look at the attached pictures.
It's a weird place for a display-related IC, but everything, including WIFI works absolutely fine. It's just the damn flicker. So maybe this is connected?
Anyone an idea / solution? Maybe even an app/kernel that messes with brightness settings?

Related

[Q] Screen Flickering - Black lines?

so I returned my sgs2 today and got a new one (old one had scratches). Now it seems to me that there is some flickering with black lines (very faded) on certain brightess settings on mainly white sites using a browser.
I noticed the flickering appears around 16% - 19% brightness settings (using "brightness level" from the market).
This flickering only appears only if "auto adjust screen power" is NOT selected, same brightness with it activated shows no flickering.
Also last but not least if plugged in with USB cable the flickering stops as well.
Can anyone re-produce this flickering?
1. Download "brightness level" from market, go between 16% - 19% (try step by step), with me its strongest at 17%.
2. Ensure "auto adjust screen power" is deactivated under Settings>Display
3. Open Internet and just look at a mostly white page
4. Ensure USB is not connected.
Can you see some slight flickering? Lots of lines across the screen?
Wonder if its just me, might go back and return this one tomorrow then
I assume no one suffers from this issue?
Sent from my GT-I9100 using XDA App
No flickering.
I get black/dim horizontal lines flickering on the display at low brightness regardless of my "auto adjust screen power" setting. I'd describe it more as a shimmering of the screen. It's very distracting - I first noticed it whilst trying out the Kindle app and it made it very difficult reading the text.
I believe it's down to interference with some radio component of the phone. I've searched various forums and haven't come across many mentions of this so maybe it's a bad batch and I'm considering returning mine. It's frustratingly variable so I hope I can demonstrate the fault in store...
I'm wondering if the increase in brightness just masks the effect rather than eliminating it. At lower brightness settings, any local differences in brightness are going to be more noticeable.
MarketMonk said:
I get black/dim horizontal lines flickering on the display at low brightness regardless of my "auto adjust screen power" setting. I'd describe it more as a shimmering of the screen. It's very distracting - I first noticed it whilst trying out the Kindle app and it made it very difficult reading the text.
I believe it's down to interference with some radio component of the phone. I've searched various forums and haven't come across many mentions of this so maybe it's a bad batch and I'm considering returning mine. It's frustratingly variable so I hope I can demonstrate the fault in store...
I'm wondering if the increase in brightness just masks the effect rather than eliminating it. At lower brightness settings, any local difference in brightness are going to be more noticeable.
Click to expand...
Click to collapse
have you noticed any change at certain battery levels?? Like if the battery was at 90% its easily noticeable, once its like below 70% I'm not able to re-produce it, no matter what I try down to 0%.
So maybe since it seems to be only from 90% - 70%, it could be to do with the current/voltage at certain brightness levels with white background...very unique problem it seems..I'm thinking of going to the o2 store but I most likely wont be able to re-produce it then and there so will they still exchange it? hmmm lets see..
Locster126 said:
have you noticed any change at certain battery levels?? Like if the battery was at 90% its easily noticeable, once its like below 70% I'm not able to re-produce it, no matter what I try down to 0%.
So maybe since it seems to be only from 90% - 70%, it could be to do with the current/voltage at certain brightness levels with white background...very unique problem it seems..I'm thinking of going to the o2 store but I most likely wont be able to re-produce it then and there so will they still exchange it? hmmm lets see..
Click to expand...
Click to collapse
I'll note down what the battery power levels are over the next week or so.
I went into the O2 store after work and reproducing the effect was indeed difficult. I had it showing the effect in the shopping centre whilst sitting down at a bench. I had it showing the effect whilst in the queue to wait for an O2 staff member. Fifteen minutes later, once I'd got to talking to the staff, it worked fine. All I could do was explain the problem and ask if anyone else had reported it. They advised I "kept an eye on it over the next couple of weeks".
Really frustrating. I'd entertain the possibility that my eyes are faulty but I've shown the effect to someone else and they agreed it was distracting.
MarketMonk said:
I'll note down what the battery power levels are over the next week or so.
I went into the O2 store after work and reproducing the effect was indeed difficult. I had it showing the effect in the shopping centre whilst sitting down at a bench. I had it showing the effect whilst in the queue to wait for an O2 staff member. Fifteen minutes later, once I'd got to talking to the staff, it worked fine. All I could do was explain the problem and ask if anyone else had reported it. They advised I "kept an eye on it over the next couple of weeks".
Really frustrating. I'd entertain the possibility that my eyes are faulty but I've shown the effect to someone else and they agreed it was distracting.
Click to expand...
Click to collapse
Yea same here. Had the manager refuse to exchange it today as i already excjanged one phone...couldnt reproduce it then and there but on on the way there i managed it..o2 sucks
Sent from my GT-I9100 using Tapatalk
Locster126 said:
Can you see some slight flickering? Lots of lines across the screen?
Wonder if its just me, might go back and return this one tomorrow then
Click to expand...
Click to collapse
Hi,
I was not able to reproduce it using your directions, but I have to say that I also noticed horizontal lines flickering on white.
I tried to reproduce it but I can't find out what it is related to.
So it's doig it just in random fashion
blade75 said:
Hi,
I was not able to reproduce it using your directions, but I have to say that I also noticed horizontal lines flickering on white.
I tried to reproduce it but I can't find out what it is related to.
So it's doig it just in random fashion
Click to expand...
Click to collapse
does it flicker with auto brightness on? You might want to download an app like "brightness level" and set it to different settings to see when/where it flickers...mine usually flickered at 17% screenbrightness when battery was at 70 - 90%
Locster126 said:
does it flicker with auto brightness on? You might want to download an app like "brightness level" and set it to different settings to see when/where it flickers...mine usually flickered at 17% screenbrightness when battery was at 70 - 90%
Click to expand...
Click to collapse
Yes I did download it and followed yur directions to try to repruce it. But I could not. I set then brightness to various level from 100% down to 0, but no luck. I have to try now when battery is at that level. Then it could be some kind of intereference. Lines I noticed on mine are very subtle and close about 1 mm
Ok, confirmed: 92% battery, brightness 17% on white or close to white screen color, there are horizontal lines like some itnerefernce/noise. Annoying
Samsung galaxy S2 screen flickering
I also have the same screen flickering problem.
it happens when the battery level is around 87-91%
Any soulution?
same here
black lines around text on white background. It disappears after a while, but is really annoying. I suppose the only solution is to change the phone?
sorry guys to hear u got the same problem....I never found a resolution to it apart from returning it to the store....once I managed to reproduce the issue infront of the manager he swapped the phone straight away.
If you got the same issue make sure you get to the store with the battery level and brightness level that shows it up, ask to go into a dark area to show it properly.
First o2 store I went to the guy refused to look at it properly and as it was light outside he couldnt see it anyways. Second o2 store I went to, the manager went downstairs with me and turned off the lights to see the flickering because it shows only on low brightness so make sure you take that into consideration when in a bright/well-lit store.
i have the same problem, it, but it only appears when "auto adjust screen power" is on. Its really a shame! Only way to fix it is to change the phone?
same here. flickers at low brightness with battery under 90%. called samsung hotline. the problem was new to them and the only idea they had was resetting the phone. tried it but unsurprisingly its no help. galaxy s2 could be great but it has just too many annoying hardware flaws
Same problem
Well I noticed this on my SGS 1 !! ... when I have PACKET DATA turned on this flickering starts. It starts really hard when i have this function turned on, but when i disable it there's nothing...
Noticed same problem on SG2 bought in Sweden
Realise this is an older topic but i have recently noticed this issue in low light with Auto On. Battery level at 85 percent. For those that had their phones replaced did the issue continue? Has anyone seen this with the yellow tint also?
Noticing this issue as well on Villain ROM 2.4. Auto brightness enabled and 90% battery.
*Edit* Just did a CWM restore to stock rooted and the flickering seems to have gone. 85% battery, auto brightness enabled.
phone swapped... problem kept
i got my phone replaced 2 months ago and was very happy with the new one since it had no screen flicker... until now. so my current sgs 2 now also suffers from screen flicker and my only options are to send it to samsung and hope to get a replacement or to live with it. and since im beginning to think that this might be a general problem i tend to keep it. although i have to admit that i dont like my sgs2 as much as i did before...

Screen brightness 100% = low frequency / flixkering

Hey guys,
I have got my I9300 for 2 weeks and I just noticed that the screen is flickering when I am in a bright environment and have the screen brightness turned to 100%.
In fact it is more like a low frequency flickering with 50 Hz.
You do not notice this if the screen is on low brightness or in a dark environment.
Did someone experience the same? Is this because of pen tile? Because of some settings although I do not remember changing anything which could do this.
Btw. I am on stock ROM with the latest update (XXALF6) and Cf root + busybox without CWM.
Gesendet von meinem GT-I9300
Hello,
I have similar problem but in my case i can notice flickering (in bright sunlight) only when phone is in power saving mode.
Try to experiment with power saving mode and let my know about result.
Cheers
I have the same problem, 1 week old phone. In bright light there is flickering, but more like 30Hz.
Only visible by my eyes if the screen is white, (maps is good for this) other people seem to notice this easier than me.
Completely gone if power saver is turned off.
My question is, is this "normal" or should I return the phone and get a new one?
/JT
So I called Samsung support and they told me that it is "by design" as power saver mode halved the refresh rate to 30Hz.
Also checked my dad's phone, also sgs3, and I think it is less prominent on his phone, but it also there. Difficult call, but I think I will keep mine.
Can't see any flickering without the power saver mode, and to be honest will probably flash CM9/10 soon anyway.

Static interferences on screen

Hi,
I've a strange and creepy problem on my prime, sometime the screen and speaker (tablet) show some static interferences, the screen messed up display horizontal bars white (in landscape ) and noisy cracking sound.
When it appends, I reboot the tablet, and the problem is gone.
I already tried a factory reset, but the problem is still here, occasonial but still here.
I am on last stock firmware. I've got the plan to root my prime, but it need to go RMA, I prefer to rid of this problem before.
Did someone encounter this bug before?
Thanks.
If it's only on the left side about an inch, then it is a known issue a lot of us have. I haven't had static in sound.
Well, no it's horizontal "static" bars wich appear randomly on all screen surface, next time i'll try to record it with my phone camera.
Something like that:
http://www.youtube.com/watch?v=nj1brJTVE0o
but far worst in my opinion. It's like flickering to me.
kalhohan said:
Something like that:
http://www.youtube.com/watch?v=nj1brJTVE0o
but far worst in my opinion. It's like flickering to me.
Click to expand...
Click to collapse
That's pretty similar to what I have, but usually it goes from the bottom all the way to the top of the screen, but only on the left side while in landscape position. It goes away if I move the screen from landscape to portrait, or reboot. Sometimes just locking and unlocking is enough to fix it. It was really bad when I was running motley's kernal 3.07 and interactive governor.
Now I don't have it as bad, I'm using Motley's lite kernal, with SIO, Ondemand, and sql patch. All I get now is a flickering lower bar and sometimes the left side corruption, but locking and unlocking screen usually fixes it.
If you'e getting this all over the screen, then that's something different and an RMA might fix it. If you're in the states, some best buys are replacing them with a 700, which is likely better.

Anyone noticing screen flicker?

Not only do I have light bleed but I'm also seeing screen flicker. I really want to keep this device but I'm getting sick of this...
The first thing I noticed when I turned on the device was the light bleed. Its pretty bad, and I normally don't mind those types of things. No flicker here though.
Sent from my Nexus 9 using Tapatalk
I noticed if I turn up the brightness it goes away.
I don't have light bleed, but I do see flicker if the screen brightness is turned down. It's reminiscent of the original Nexus 7, which had the exact same problem.
I have the flickering too...really annoying. I was hoping that this would replace my iPad but it's not looking good. Although lollipop is pretty amazing so far.
Does it only happen you adjust the brightness? If so, i dont think its a big deal as long as it doesnt happen during actual usage.
I noticed the flicker issue when I first was using it. I then turned off auto brightness from the main settings and started using Lux Auto Brightness and the issue has been resolved as far as I can see. I suspect this is an issue with the Lollipop build's brightness manager and not a hardware issue from the backlight. Also as far as bleed goes, there is apparent bleed when viewing the screen at an angle and looking directly at the edge, however I have found that it is a complete non issue in normal use (even in a fully dark room), which stands in stark contrast to my Nexus 10 which has noticeable edge bleed when viewed straight on.
No Flicking here
No flickering here either.
No flickering, but the auto brightness is very weird! It goes from extremely bright to extremely dark without me actually moving, same light conditions?
No flicker here!
Well, I guess we can all admit screen flicker is of the norm of Tegra.
Im seeing flikkering too.....
Only when brightness is low.
Remind me why Google/htc did not decide to use a 64 bit Qualcomm processor instead? :-\
Do you think that this issue can be solved via software update, or is this issue hardware related, and therefore cannot be fixed easily
bobmarleo said:
Do you think that this issue can be solved via software update, or is this issue hardware related, and therefore cannot be fixed easily
Click to expand...
Click to collapse
considering that not everyone has it
So i say no
This issue seems to be related to auto brightness/adaptive brightness: The same brightness level set manually doesn't flicker.
Seems to be a software issue to me, and it seems highly likely every Nexus 9 flickers with auto brightness on (and at low relative brightness setting) in low light environments.
PartyMango said:
This issue seems to be related to auto brightness/adaptive brightness: The same brightness level set manually doesn't flicker.
Seems to be a software issue to me, and it seems highly likely every Nexus 9 flickers with auto brightness on (and at low relative brightness setting) in low light environments.
Click to expand...
Click to collapse
But, my screen flickers when I am on a constant brightness level. But, it doesn't show up as much when the screen is on at full brightness, just when the screen is at half brightness or just below half.
bobmarleo said:
But, my screen flickers when I am on a constant brightness level. But, it doesn't show up as much when the screen is on at full brightness, just when the screen is at half brightness or just below half.
Click to expand...
Click to collapse
I guess we aren't experiencing the same issue, then: My screen only flickers with adaptive brightness enabled in low light conditions, seems like it is constantly readjusting the screen between two brightness values.
My Nexus 9 doesn't flicker at any constant brightness setting.
Yep, my Nexus 9 flickers as well.
About 15-20% brightness (fixed). It doesn't flicker all the time and it goes away if you change the brightness level or even by itself if you change the app you are using.
This leads me to believe this might be a software issue (N7/2013 had this too when it came out).

[Q] Low/dim backlight after screen replacement

Hey there!
I'm currently trying to repair an Xperia Z2 that had water enter its chassis. The initial fault was that the backlight was completely non-functional with the screen still working as you could make out stuff when shining a bright light on the display. I read that this can be due to a blown fuse on the board, but before attempting to solder, I decided to get a replacement screen first.
The replacement screen has the backlight working, but it's very dim as if it was fixed to the lowest brightness setting. Naturally, I tried changing that in the Android settings, but to no avail. Various combinations of settings like turning the adaptive brightness on or off also does nothing. I tried a factory reset as well, but the issue persists.
Could this still be due to a bad fuse? At the very least, the old screen definitely had a defect since the new one has the backlight working at least somewhat. I'd be surprised though if there was a fuse solely responsible for letting you control the backlight brightness.
I checked one of the fuses commonly suggested to be responsible, as explained in this post. It's still conducting electricity though, so I doubt that's it. The other fuse is near the CPU below the heatsink, but I had trouble testing that since it's covered with some non-conducting substance like a resin of some sort.
What do you think? Any help is appreciated!
Hi did you ever find out what the problem was?, because i have the extact same problem with mine after water came into it and i replaced the screen.
any info could be of help

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