tldr; Turning auto brightness off and setting brightness to the lowest might work.
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.
warranty of products has been exended till half of july or something like that, check it on the internet and if it is still valid go ahead with a warranty replacement
This helped me! Bought my S9 used but in mint condition, it was working perfectly the first 8 hours. Then I clicked the power button twice to see my lock screen and all of a sudden my screen looked like it had some green-tinted old timey film grain filter on it. I was worried I somehow damaged the phone or that it came with underlying damage, but then I discovered that on the lower and higher brightness settings the screen looked fine. Downloading this app makes the screen look fine on the brightness levels in between (you just adjust the brightness through the app instead of through the phone widget). So seriously, thanks!!
I have the same problem.
After the last update, I pressed the power button to turn the screen off, than pressed again to turn back on, than a green glitch appeared. Since than I have the greenish tint 😞 and low res look here and there.
I hope Samsung reads these, and do something.
Galaxy S9 T-mobile, Hungary (Exynos)
They won't, but I haven't had any issues since I downloaded the OLED Saver app! Fair warning, if you try to screenshot anything you'll need to adjust your brightness first, all my screenshots were looking super dark just because I had the OLED Saver brightness way down lol
Thanks, I will definitely try it!
Does it help with the glitch witch happens when you turn off and then back on your screen?
Which glitch are you referring to? Something different, or the dim screen and green bars? I haven't had any screen issues at all since downloading it.
I have the same problem after my last updated on my Galaxy S9 about 1 month ago. I didn't know about low/high brightness and OLED Saver, it helped me a lot, thank you guys. But my warranty was gone and I think samsung have to do anything to help us, a lot of people getting the same problem with the same update.
I am having the exact same issue since the MAY 2020 update.
1. IF you do some activity for 15-20 mins (or more) and lock the phone and try to do some other activity immediately and unlock the phone then you will see flickering/black screen for 3-5 mins.
2. if your phone is hot by virtue of any activity and locked then unless it is cooled off, you wont be able to do any work on the phone.
This is becoming a major problem and sometimes not able to do very important tasks. e.g.
When I turn off the screen, and immediately try to wake it, the screen stays black, only a small portion of the screen at the top flickers in green/black (I can at at least see the time, but nothing else).
Checked Oled saver yesterday, thanks for the tip. At low brightness I wasn't able to watch a darker toned video, because it looked like a blocky yellowish-greenish mud.
Now with oled saver it is still not perfect, but almost
And I forgot...
If I do the same (turn off and back on the screen in a few seconds) with oled saver, the screen doesn't flicker! But it gets a little yellowish tint than.
If I turn off the screen and wait 10 seconds before waking it up, everything is fine!