2011 iMac screen goes and stays black
Ready to throw it out the window! I can hear it start up but the screen is black. Took it to get fixed and they reset the LCD cable and it worked at the store got it home and back to black. Now what?
I bought an iMac with this problem for a good price to solve the problem. I got it temporary worked around, maybe you can try it.
Unplugging the power for a while and putting display brightness to lowest seem to have worked around the problem for a while.
I think the built in power adapter or backlight board is the issue. These are both always powered when plugged in.
This week this workaround didn't work anymore and I'll replace both. I'll let you know what the culprit was.
Dennis van der Pool
I may have hacked a solution to the iMac screen, specifically I think the iMac 2011, going dark or just black!
I have an iMac 2011 someone donated to me because the screen went dark after brightness of 3 or 4. I’ve used it a long time, but recently its screen just failed to turn on. Tried PRAM, SMC, even fresh copy of High Sierra using an external drive. Nothing.
Potential Hack for others to try, or learn from.
So I got out my older iMac 2009. I use the iMacs for 2nd monitors, using their Target Display capability. I plugged in a DisplayPort cable from the iMac 2009 to my MacBook Pro 2014. Everything is working fine, just using the older iMac. I keep wondering about solving the black screen on the iMac 2011.
So I then shut down the iMac 2009, unplug cables. Get the iMac 2011 up on the desk, plug in the cables, including the DisplayPort to the Macbook, and WOW, up powering up the iMac, the screen came back alive!!! And once the iMac
Please update this community if you test this and find it works, doesn’t or any other information to consider. Here are the steps that worked for me.
Specifics to what I did, not sure what steps could be modified, clarified, or removed, but this is what I did. Posting hoping this leads to a good hack for others to revive older iMacs. Please test and comment for others to learn more.
MacBook Pro 2014 i7 / Big Sur (TB2 compatible)
iMac 2009 27” i7 / High Sierra (DisplayPort only)
iMac 2011 27” i7 / High Sierra (TB2 compatible)
Cables: Thunderbolt 2, DisplayPort.
I fixed it by replacing the faulty GPU. Same issue; only video at the external video output.
I tried another LCD, inverter and powersupply. No succes, so I replaced it with a K1200M with custom firmware.
for this issue it’s crucial to know if the external screen is attached as secondary or primary.
logon screen at secondary screen: LCD is not being. Initialized due to loose connection.
I found out troubleshooting that the external screen is mounted as primary when I disconnect the internal lcd partially.
The external screen get primary if the internal lcd is not connected right. if you get a loginscreen at the external screen, this might indicated a loose connection.
with the logon screen on the faulty internal LCD you will get a blurred background visible on the external. In my situation this was a result of a faulty GPU that didn’t feed the internal LCD properly.