Late 2014 5k iMac screen goes black when playing videos

GavrielTech wrote:

I migrated then did the whole process again with syncing my icloud account.

i got this machine used, then formatted the fusion drive with a fresh install of Catalina

i used a new account (no icloud) cause i misspelled my user name,

Screen blackouts,

i then created a new user linked to my icloud account

Screen black outs continued

only the paid etrecheck shows so e more details, the last time i posted a report here my thread was taken down..dunno why..

If the screen black outs occur with a fresh reformat of the disk followed by a fresh MacOS install WITH NO USER MIGRATION AT ALL and no putting of anything on this fresh install aside from the MacOS and Apple apps that were originally installed with the MacOS, no exceptions, then you have a hardware problem that won't go away until it is diagnosed and repaired.

The fact that the problem goes away in Safe Mode, that could be because Safe Mode disables certain hardware accelerators for graphics, and that hardware is broken or faulty. Or it might be something else ...

Apple's policy on servicing older Macs is documented here:

https://support.apple.com/en-us/HT201624

"Service and parts may be obtained ... for up to 7 years, subject to parts availability ... Apple discontinues hardware service for certain technologically-obsolete products. Your device is supported by ongoing OS updates and backed by a network of more than 5,000 Apple-certified repair locations that you can count on if something unexpected happens."

Your Mac is more than 7 years old, so Apple no longer stocks parts for it and won't service it anymore. Personally, I would drive the 140 miles to figure this out . I have working Macs from 2008, 2010, 2013, and 2016, as well as new ones. Older Macs can often be fixed to be like new. I think it's worth finding out. Before doing that I would recheck, back up all files, then erase and fresh install and migrate NOTHING over, just see if the problem is there on a plain vanilla version of your Mac. If you have already done this, then it seems that your hardware is broken.

I don't see any other options. You have obtained a used computer ("Caveat emptor"), old enough that Apple won't service it anymore, perhaps it had the problem before and that's why the seller sold it to you. Buying computers used from private parties who don't offer a warranty can be dicey. Anyway, I suggest making one last try on the clean install with zero files or software migrated in, to test again. Then if still not working, it's time to make the trek to the authorized repair center (or find a safe way to ship to one), or simply go with a new Mac. The new M1 Macs are spectacular.

You should have your iMac checked by an authorized Apple service center, because you are experiencing a video/graphics problem, and booting into safe mode typically disables certain video accelerators. So you are using video hardware differently in safe mode. Your graphics/video hardware is suspect. I think you have ruled out most other possibilities with your fairly systematic testing.

I would not take your computer to Apple, but rather to an independent repair shop that is certified by Apple. Those shops have the freedom to work on older Macs, in fact many specialize in diagnosing and fixing older Macs. There is one a few miles from where I am and they replaced the SSD and battery in our 2013 MacBook Air for about $50. Apple no longer sells parts for this "obsolete" Mac but they directed me to OWC and had me purchase the Apple-compatible parts at very low cost and bring them in with my Mac where they did the work. These Apple-certified shops have access to much more in depth diagnostic tools for your hardware which are far superior to the Apple Diagnostics that come with your Mac. This Apple certified shop even shows up on the Apple web site where one can go to make online appointments for service. You are correct that Apple itself stops working on older Macs, but these independent (Apple certified) repair shops still do this work.

Also, bring your power supply in as well, they can test that for you too.

@GavrieITech - After your drive format and clean install of the OS, did you migrate from a backup? If so, was it just the User data or was it everything? If it's a 3rd party software conflict (and it sounds like it is), restoring more than the User data from a backup is just re-introducing the problem to the freshly installed OS. The recommended way to start fresh after a disk wipe and a clean install of the OS is to just migrate your User data and then re-download the apps you use. Lots of cruft accumulates over the years, especially if you've been updating the OS in place.

If you post the Etrecheck report using the "Additional text" button we might have a better idea of what's going on with your system.

You have done a lot of very good trouble shooting - Bravo.

But it might be time to consider Find an Apple Authorized Service Provider and have them evaluate the computer for possible Video Card issues.

Suggest downloading the Application Etrecheck directly from a well Respected ASC Contributor. 

Disclaimer: I am not affiliated with nor receive compensation from the Developer.

The application is free or paid from added features. 

Run the application with Full Disc Access ( Security & Privacy - Full Disc Access ).

It will take a Snap Shot -  both the hardware and software.

 The Report will Not Reveal Any Personal Information. 

Post back the Full Report - copy and paste - using the Additional Text Icon ( 3rd Icon to last )

We can have a look at the report for possible issues and may have possible suggestions to resolve the issues.

Any Third Party Applications that will interfere with the normal operation of the OS, alter, modify, remove or delete or attempt to do so is an invitation for disaster and may require a Reinstallation of the OS.

This includes AntiVirus, Disk Cleaners, Disk Optimizes, UnInstaller etc.

I am convinced the AHT is believed, by Owner of this question, is the same as the Etrecheck Report and thusly reticent to use the Application.

That specific issue has been covered to the best of my ability

GavrielTech wrote:

I did share etrechevk reports before but according to Apple its malware

copy pasted

EtreCheck, a 3rd party app that does not meet Apple's requirements for acceptance into the official Mac App Store, has been shown to contain files that have tested positive for malware according to numerous authorities on the subject.

The app has been shown to contain OSX.Genieo and PUA.OSX as well as have other dangerous code, according to top anti virus companies including McAfee, TrendMicro and AVG, Avast, AegisLab,

No, Apple does not say Etrecheck is malware.

Your quote is from a site called "howtotellifyourmacishacked" which I guess you are trusting to be the truth. It appears to be promoting a variety of anti-virus software companies. I think they have a monetary interest in promoting this type of misinformation.

Apple imposes certain requirements on software that it puts in its App Store. Some developers prefer to sell their software directly to users; in fact, some offer two versions of their software, one in the App Store, and another downloadable directly from the developer web site and that latter version often has more functionality. An example of this is DaisyDisk.

GavrielTech wrote:

There where many ways to check compare graphics extensions which worked fine in "safe mode" in order to enable disable anything causing this in Catalina, BigSur etc

Etrecheck is nothing but malware; no info about extensions and not worth paying for either

This is complete garbage.

Etrecheck is free to use, and absolutely NOT malware. It does not in any way modify a system. It is a diagnostic application that produces a report, so users here can see what may be causing problems to the OP.

It is an invaluable and indispensable tool, used here thousands of times, for the purpose it was created for.

I am not sure if you are trolling or just misguided, but please don't gratuitously disparage the best tool we have to help others.

Etrecheck produces a report that mere mortals like us can read, in an organized fashion, collecting valuable information in one place. It has helped us solve hundreds of cases around here. Yes, the information exists in the system - that is how Etrecheck is able to provide it, duh! - but it is not easy to gather, especially for less knowledgeable users.

All they have to do is run this application and post ONE report here.

Most users cannot open the Console, and figure out things from cryptic system reports, and they should not have to.

And if the threads you refer to are the solution, fine! You could have posted that before.