Why Does My iMac Screen Flicker or Just Not Work?
I have an early 2009 21.5 inch iMac. The vast majority of the time, my iMac screen doesn’t work. I power up the iMac and the screen flickers once and then just turns off, but the machine itself runs fine, and there is video output to an external display. The problem started a few years ago and it started as just some minor backlight flickering, but eventually the screen stopped working completely. I have gone through all the basic troubleshooting steps (I.e. reset the NVRAM and PRAM) and none of them work. The screen only works when I leave it sitting for a long time (sometimes as long as a month), and then it powers up fine, but after about 15 minutes of use, the screen starts flickering and then just turns off completely. Any and all help would be much appreciated. :)