iMac screen goes black.
I have a 2010 27” i7 iMac that has decided it no longer wants to display the display.
For the past few months the screen would randomly shut off every once in a while, almost as if it was put to sleep. Usually a few clicks on the mouse or a couple of taps on the power button would wake up the monitor. Then, about a week ago it became much worse. When starting up, the display will work for about 4 or 5 minutes before going black. Waking it from a long sleep will also see it work for a minute or two at most. Thinking it may be a heat issue I cranked the fans using iStat menus with no change. I’ve tried safe boot and resetting the PRAM, neither worked. Also watched the console when things go dark but didn’t notice anything that stood out. Luckily I still have our old Apple 20” lucite Cinema Display and an Apple DVI to ADC display adapter so this has become our “second” monitor.
I did open up the iMac in the past, once about 3.5 years ago to add a ssd drive when the spindle drive became too slow, and again a year later to replace said spindle drive with another ssd.
This computer doesn’t owe us anything, and it will be replaced after the keynote next week, but I was just wondering if there was anything else that I could try?
The most common reasons for the black screen of Mac:
1. installed a new macOS or macOS update
2. restarted your mac
here are some suggestions for DIY verification:
1. check the power supply
2. check the display brightness by pressing F1 and F2
3. reset NVRAM/PRAM
4. boot into safe mode: pressing Shift key while booting
5. run First aid in recovery mode
6. reinstall macos
have a nice day
I have had the same issue with my iMac mid-2011 27 i7.
The screen will go black when I turn the brightness up, this was happening for a number of months and I could only have the screen on 3 bars of brightness
I covered the sensors at the top which did not work
The only thing that worked was pushing in the LCD screen casing at the top (without the glass)
So I took the front screen off and made sure all the metal foam connectors that connect to the screen and glass were all connecting by pinching them to give them more volume as they had become compressed over time. This worked a treat and now can have full brightness, The same problem reoccured so I repeated and all good again.
I would also recommend getting mac fan control and having fans at max as the iMac 2010 and 2011 run too hot and burn out.
Hope this helps
If the screen goes black, green or stripey and the computer won't reboot this will be your graphics card and you will need to strip the machine and cook the graphics card in an oven, I have done this several times and it has worked each time.