2015 27" iMac has pink edges ..anyone else?

[onnomark]

I am not experienced enough with the 27inc imac and removing / attaching the display and its effect. I have a 21 inch imac which I opened several times and it does not have any pink edges. So it seems it is really about the 27 inch displays.

I have good results removing ghosting and pink edges through my script which alternates between no and very high back light intensity. It alternates about 15 times in 30 seconds and it really helps removing the pink edges and ghosting.

Cleaning the vent inlet (lots of dust) seriously slowed down the appearance of the pink edges. I am using the imac during coding which is my daily job. Now I have days where the edges appear at the end of the day where the whole system is a lot warmer than in the morning. Before cleaning the pink edges appeared after a few hours in the morning.

To me it is still a heating issue with the potential risk of damaging the lcd (burn-in) when the heating issue is ignored.

I just received my tools to remove the screen, upgrade the nvme, remove the stupid harddisk and clean the heck out the complete system. The speakers are actually claiming a lot of space which also means the airflow is minimal in those area's. Not sure yet what I am going to do to enhance the airflow / cooling but it is my main goal to seriously improve it. Not afraid of drilling holes to enhance cooling but I also realize the recent experience where removing the memory door actually made the pink edges occur faster!

 

[onnomark]

I recently replaced the failing internal HDD with a SATA SSD on a 2017 5K iMac and noticed that before removing the screen there were essentially no pink borders but right after reassembly the sides had a slight tint. Could it be that the pressure I used to cut the monitor open might have damaged something to accelerate the pink edges and it’s not only about heat buildup?
Could be placebo but I intentionally examined the screen before I did anything to see if it changed, and apparently it did.

I just realized that there are suggestions that when attaching the display again there might be light entering through the gap between the chassis and the display. You can easily validate this by using non-transparant tape and stick that to the side of the display. It should overlap the space between the glass and the aluminium housing. Easy to try, quick validation

 

[Nermal]

My 2020 is starting to develop these pink edges now

It's nowhere near as noticeable as in the photos on page 1, but it's starting to creep in on both the left and right edges.

Edit: Actually, take this report with a grain of salt. I probably first started noticing it a couple of months ago, which isn't long after I replaced the fan. It's possible that it's just light coming in the edges if I didn't close it back up properly (although would that be pinkish?).

 

[PaulD-UK]

@Nermal A few months ago I bought a non-working iMac Pro, which from it's serial number was produced 2020 or later.

It came from a graphics design studio (hard life?) and when I removed and tested the screen there was the most pronounced pink edge colouration I've seen.

My initial thought was that it must have been the result of the machine been frequently used for rendering for hours and hours, and so it had run very hot - and eventually failed.

Others have said it may be influenced by opening the iMac, and disturbing the screen in some way.

Anyway I hope to investigate further on whether the pinkness can be reduced in the same way as it can for 2015 iMacs, by running a specific flashing image sequence for some time - something like that...

When I get a round to-it, haha.

 

[onnomark]

@Nermal A few months ago I bought a non-working iMac Pro, which from it's serial number was produced 2020 or later.

It came from a graphics design studio (hard life?) and when I removed and tested the screen there was the most pronounced pink edge colouration I've seen.

My initial thought was that it must have been the result of the machine been frequently used for rendering for hours and hours, and so it had run very hot - and eventually failed.

Others have said it may be influenced by opening the iMac, and disturbing the screen in some way.

Anyway I hope to investigate further on whether the pinkness can be reduced in the same way as it can for 2015 iMacs, by running a specific flashing image sequence for some time - something like that...

When I get a round to-it, haha.

The script is working well, not fixing the root cause but cleaning up the pixels so to say. I tried to share it through the forum but it got removed due to forum terms and conditions. Second, I am not using apple operating system but Linux so I have no means validating the script on apple OS .

But you can ask chatgpt to write such script for Mac OS. I can share the prompt information you can use to generate it.

 

[onnomark]

My 2020 is starting to develop these pink edges now

It's nowhere near as noticeable as in the photos on page 1, but it's starting to creep in on both the left and right edges.

Edit: Actually, take this report with a grain of salt. I probably first started noticing it a couple of months ago, which isn't long after I replaced the fan. It's possible that it's just light coming in the edges if I didn't close it back up properly (although would that be pinkish?).

That's interesting that it might be the result of removing the display. If so, I would expect using some non transparent tape could be used. Like the black electrical tape. Just tape the side which should block any outside light from entering the chassis / display.

Do you observe the pink edge becoming more visible when the IMAC is starting to heat up? In other words: a cold morning start would not have pink edges but later in the day the pink edges start to show?

 

[onnomark]

The script is working well, not fixing the root cause but cleaning up the pixels so to say. I tried to share it through the forum but it got removed due to forum terms and conditions. Second, I am not using apple operating system but Linux so I have no means validating the script on apple OS .

But you can ask chatgpt to write such script for Mac OS. I can share the prompt information you can use to generate it.

Later this week I might have time to publish the script on GitHub which allows you to download it. If you can validate the script and capture console messages in case it does not work 100% i can update the script until we have ironed out the bugs.. if any occur.

 

[onnomark]

I hope I am not violating forum rules sharing the prompt instruction. I am also not sure it will work on apple OS since I don't have Apple OS running on my iMac's. But if someone is willing to test (at own risk) that would be great. The prompt includes requirement nothing should be written to disk.

The chatgpt prompt, copy past below into chatgpt:


Generate a SINGLE, standalone Bash shell script for macOS that performs
an advanced LCD pixel refresh / ghosting cleanup.


HARD REQUIREMENTS:

- Must be ONE file only (single .sh script)

- Must NOT rely on external tools or Homebrew

- Must work on macOS (Intel + Apple Silicon)

- Must use native macOS APIs (Swift + Cocoa compiled at runtime)

- Must run fullscreen, borderless, across all Spaces

- Must auto-exit when finished

- Should not write anything to disk

- Should only run in memory


FUNCTIONAL REQUIREMENTS:

The script should compile and execute embedded Swift code and perform,

in this order:


1. Rapid black/white flashing (pixel discharge)

2. RGB color cycling (subpixel balancing)

3. High-frequency checkerboard inversion pattern

4. Moving vertical or horizontal sweep bar


CONFIGURATION:

- Flash counts and delays should be configurable at the top of the script

- Total runtime around 2–3 minutes


USABILITY:

- Script must print clear start/end messages

- No user interaction required

- Safe to terminate via Force Quit


OUTPUT FORMAT:

- Output ONLY the final Bash script

- Include clear comments in the script

- Do NOT include explanations outside the code


This tool is meant to reduce temporary LCD ghosting / image retention,
not permanent burn-in.

 

[Nermal]

That's interesting that it might be the result of removing the display. If so, I would expect using some non transparent tape could be used. Like the black electrical tape. Just tape the side which should block any outside light from entering the chassis / display.

Good thought. It made no difference.

Do you observe the pink edge becoming more visible when the IMAC is starting to heat up? In other words: a cold morning start would not have pink edges but later in the day the pink edges start to show?

There might be something to this. Yesterday was a pretty warm day, but today's noticeably cooler and I think the pink is harder to see. But I don't know for sure, and I know that human memory is very bad when it comes to colour.

 

[Sippincider]

Early 2019 27" i9, and getting noticeable pink edges here as well.

Temperature and lighting don't seem to make a difference. Was purchased as an Apple refurbished months
after launch. Has definitely seen its use and been ran hot in a prosumer environment.

Machine is off support (won't run Tahoe, for better or worse...) so will be replacing soon anyway.

 

[calvinchan.hkg]

I am not experienced enough with the 27inc imac and removing / attaching the display and its effect. I have a 21 inch imac which I opened several times and it does not have any pink edges. So it seems it is really about the 27 inch displays.

I have good results removing ghosting and pink edges through my script which alternates between no and very high back light intensity. It alternates about 15 times in 30 seconds and it really helps removing the pink edges and ghosting.

Cleaning the vent inlet (lots of dust) seriously slowed down the appearance of the pink edges. I am using the imac during coding which is my daily job. Now I have days where the edges appear at the end of the day where the whole system is a lot warmer than in the morning. Before cleaning the pink edges appeared after a few hours in the morning.

To me it is still a heating issue with the potential risk of damaging the lcd (burn-in) when the heating issue is ignored.

I just received my tools to remove the screen, upgrade the nvme, remove the stupid harddisk and clean the heck out the complete system. The speakers are actually claiming a lot of space which also means the airflow is minimal in those area's. Not sure yet what I am going to do to enhance the airflow / cooling but it is my main goal to seriously improve it. Not afraid of drilling holes to enhance cooling but I also realize the recent experience where removing the memory door actually made the pink edges occur faster!

Hi onnomark,

I have pink edges issues on my iMac 27 (2019). Can you share the script for us to download to let me try if the pink edges issue can be solved? Thanks so much.