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JoySwirl
User level: Level 1 (12 points)

M3 iMac display failure after 2 years 10 months

I’m sharing my experience of a display failure on my M3 iMac, including the symptoms and repair outcome, in case it is useful to other owners.

My iMac:

• 24-inch M3, 2023, pink.

• 24GB unified memory and 1TB SSD.

• Purchased in November 2023.

• Failed in September 2026, aged approximately two years and ten months.

One day the screen flashed once and then never came back on. There had been no previous screen symptoms, knocks, spills or other damage. It is used at home for personal and business purposes, usually five to eight hours a day, Monday to Friday, and switched off overnight.

At the Apple Store, staff connected an external monitor, but that also showed nothing. Their initial suspicion was a logic board fault.

After roughly two weeks, Apple told me the fault had actually been the display, which they replaced. The repair invoice lists display part 661-35878 and labour, with no replacement logic board listed. The iMac is now working again.

My husband and I have used iMacs for more than 15 years without experiencing this type of failure. He purchased the same model at the same time, in a different colour, and his continues to work normally.

I would appreciate a technical explanation of why the external monitor also showed no image during the initial assessment, when the eventual repair was a display replacement. Can a fault within the built-in display affect external video output, or could another aspect of the initial test explain this?

Thank you.

Posted on Oct 6, 2026 7:02 AM

2 replies

MartinR
User level: Level 7 (27,833 points)

Oct 6, 2026 7:22 AM in response to JoySwirl

There is no way for us to know what actually occurred in your iMac. We would have had to be the technician who actually worked on your iMac.


In general terms, the failure of both the internal display + an external display would lead one to suspect the video controller, which is embedded on the logic board. But it appears that upon further (deeper) diagnosis the technician determined the problem was only the display panel. The front Apple staff who connected the external display would not have had the necessary equipment to do more than a cursory diagnosis.

HWTech
User level: Level 9 (78,350 points)

Oct 6, 2026 9:16 AM in response to JoySwirl

I can only tell you what I have personally observed while supporting my organization's Macs. With the Apple Silicon Macs it is not always possible to show video on the external display......even the later USB-C Intel Macs had some of this behavior to a lesser extent.


It can be very difficult to get useable video onto the external display. At best you may get an extended screen which may or may not allow you to modify the Display settings to change the main display or enable mirroring. Sometimes macOS may have some mandatory window on the built-in Display that must be dealt with before you can do anything else (usually occurs after a minor macOS update patch).


In fact you may first need to blindly log into macOS before you are able to do anything with the external display. You may also have to jump through hoops to be able to launch & access System Settings on the external display so you can make changes to the system to either mirror or make the external the main screen.


If the system does not boot directly into macOS to allow use of the extended display, then any messages or screens may be forced onto the built-in Display Assembly. This can happen even if the built-in Display Assembly is physically disconnected as well. Apple has made some things forced to appear on the built-in Display unlike older Intel models where the external display would become the main display.


What people need to realize is the old Apple has been dead & gone for over a decade. This is the new Apple where their computers and macOS are being transformed into glorified iPads and iOS. Do I like it? No. However, I can understand what Apple is doing here.


You can provide Apple with product feedback here:

Product Feedback - Apple


Originally posted at discussions.apple.com/thread/256371337