iMac has random black screens but works fine in Target Display Mode?
Hi,
I have a 2010 27" imac. It has the latest OS on it and has always worked fine. In the last week the screen has started going black randomly. If I shine a torch at the screen I can clearly see the computer is still on and working fine, just with the backlight out.
However!
I also have my gaming PC plugged into the iMac and have been using as my monitor for years. When I command F2 and go into target display mode with the PC, the imac works flawlessly as a monitor and the backlight stays on all the time.
If I swap back to the iMac the screen will be on but normally only for a few minutes before it blacks out again.
I am puzzled and hope someone out there has an idea what this could be.
Thanks in advance.
Is this a good question?
5 Comments
ok checked corners - nothing set. Sleep time is 15 mins. When it happens the only way to get the backlight back on is to command F2 and back. Nothing else wakes the screen.
by Jim F
Let's try one last thing here, shutdown the system and then pull the AC cord leave it unplugged for a good 10 minutes then restart the system. Did that fix it? If not I'm suspecting the PRAM battery needs replacing.
by Dan
Did the 10 mins thing. No change. Is there any point in restoring from an earlier backup or is that a waste of time?
by Jim F
I also noticed that the system clock reset during the 10 mins turned off. Would that indicate the battery is dead and if it is why would that affect the backlight?
by Jim F
Yes, that confirms the PRAM battery needs replacing
by Dan