S9 Plus Screen Flickering, Green Tint/Bars, Black Screen Issue

[Sohel]

tldr; Turning auto brightness off and setting brightness to the lowest might work.

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I have been using the Exynos model for past two years. About a month ago or so the device first exhibited screen flickering issue all of a sudden. Green bars, black screen area, sort of animated and laggy. For the time being, only immediate lock-unlock attempts were causing the screen flickering (meaning, when I unlocked immediately after locking the device, the screen was causing trouble). I left it as it was and just kept avoiding immediate unlocking. Anyhow, after maybe a couple of weeks, out of nowhere the screen appeared to be flickering permanently and the device was rendered totally unusable. I tried doing some troubleshooting, factory reset, odin flash, etc. and none of them worked. Could not visit a service center in this lockdown situation.

Later, I figured that in my case, the screen is working at a very low brightness and partially working at full brightness but not working at all in between. It's just 90% black, 10% green and such. For about a week, I have been using it at a low (i.e. 5% to 10%) brightness. Left the auto brightness, always on display, and screen-on iris recognition settings turned off. I use Bixby or Google Assistant to set the brightness if I can't see the screen. With these setup, it's working for now. As of the software, I am on the latest firmware (May 2020 security patch).

From my observation, the issue had something to do with heating. I am not certain but I feel like the issue occurs more frequently if the device is used for prolonged period and heated up due to gaming or mobile data usage. I would suggest anyone who is stuck during this time before you can repair, should your device work at a low brightness then clean up the phone, get rid of unnecessary apps, games and reduce/avoid long usage that cause heating. Also leave the medium power saving mode on as it limits the CPU usage which supposedly help reducing the heating as well. Do not use night mode, gray wallpapers, etc. Use light or colorful backgrounds, apps, etc.

Thanks. Stay home and safe.

[Renish]

Replacing the battery won't help; it's an issue with the display screen, so replacing the display might resolve it. However, at that price, you could purchase a new phone.

Interestingly, I have stored a paper in my drawer that marks the exact location of the PIN number and swipe dots. It's there for emergencies when the screen goes blank, and I need to enter my PIN or swipe.

[kaehndan]

Great tip!
Has anyone figured out a workaround for during calls? Seems like you can't trigger the AOD during a call, and if you need to "press 1 for x option" during a call that can be tricky.

My plan to build Lineage for this phone and try to see if I could work around the issue with some kernel hacking was dashed to smithereens when I learned that modern US Samsung phones can't have their bootloaders unlocked 😕

[wilsonpenha]

I fixed it by doing the following:

1st with very difficult step to turn low or very high brightness

2nd install screen dimmer which takes control of the brightness and fix the green lines and black screen

3rd use screen dimmer to increase/decrease brightness

Now an unuseable phone is back to life

I also saw that simple procedure of remove and put back the screen flat cable fix the issue, 

It seems issues with old s9

Good luck

[wilsonpenha]

 

  

[mmedia1]

Thanks, but the instructions are unclear. What screen dimmer are you using and what does "1st with very difficult step to turn low or very high brightness" mean?

[wilsonpenha]

Hey sorry

The hard part was to find the brightness bar to be able to set it to low to be able to see the screen and then install the screen dimmer - reduce flicker from REWHEX and fix the issue

[Baker111]

thanks