iM 4,1-14,4 iMac 27" late 2012, black screen.

[rin67630]

It's now the third iMac 27" (late 2012) that I see ending up with a black screen.
It appears that the graphic card is OK, it works on an external screen.
Has someone found out, if it is the screen which is defective(and the iMac would work if the panel is replaced) or something else on the logic board, the panel being OK?

 

[Juicy Box]

My daughters late 2012 iMac just recently started having a similar issue, the screen stays black for a very long time, and then the bar that shows on the Apple screen when it’s booting, it only has a tiny bit of progress and just stops there. I haven’t had time to troubleshoot, I’ll try to get to it this week.

 

[Chuckeee]

Is the screen on but black or is the screen actually off?

 

[Fishrrman]

Try plugging in an external display of some kind.
This way you can tell if it's the display (itself), or something else wrong.

My advice:
Don't buy any more iMacs. You seem to have bad luck with them...
Next time, get a Mini and a 3rd-party display.

 

[rin67630]

Is the screen on but black or is the screen actually off?

The screen has no content, it's not just the backlighting.

 

[Nguyen Duc Hieu]

The screen has no content, it's not just the backlighting.

On the external display, can you check the Display setting to see whether both displays are recognized?
Anyway, this usually caused by a hardware failure and not repairable by yourself.

 

[rin67630]

On the external display, can you check the Display setting to see whether both displays are recognized?
Anyway, this usually caused by a hardware failure and not repairable by yourself.

Both displays are recognized, only the internal display has no content, only a faint backlight.