Running it with a dimmer setting for screen brightness also worked. Waking it would re-activate the backlighting, at least temporarily.

He noted that in his case, putting the iMac to sleep through a keyboard shortcut (Control–Shift–Power button or Control–Shift–Media Eject) or by pressing and quickly releasing the iMac’s power button. While he replaced the screen, the problem came back. Yet another had an issue with a 2009 iMac’s backlighting: sometimes the monitor works, but when the backlighting fails, you can’t see anything on the display. Pressing on the affected spot could restore light temporarily.” You’d need to find a shop that was willing to disassemble and reassemble a Mac to fix this problem. That gap caused periodic screen blackouts. “There was a gap in the thermal paste that prevented the screen from making full contact with a sensor along the bezel. Jefferson said a friend’s iMac had a similar problem due to an imperfect upgrade by a previous owner. It might cost $100 or more to have someone qualified crack the case and look for signs of failure, at which point unless they’re handy with a soldering iron and it’s something that can be fixed with molten tin and lead, it won’t be worth repairing. I suspect the repair shop only ran hardware diagnostics via software, which wouldn’t reveal this, and didn’t open it up. In movement, it might have been jarred, or the repair facility might be heavily air conditioned or not at all, while Cecil’s home is the opposite. With modern manufacture, that sort of nonsense is much less likely, but given that moving the iMac into a different location made the problem impossible to replicate lends credence. Banging the set jarred the discontinuity in the solid-state circuit that did color decoding. (As a child, my family had a color TV set, but when it heated up, it shifted to black and white. While I haven’t seen this recently, in my youth-when I was more hands on with soldering irons and circuits-it was relatively common to have faults that only materialized under certain circumstances in which heating or cooling caused expansion or contraction that caused a temporary gap in whatever conductive material was passing electricity. Without laying hands on the computer, my guess is this is an electrical fault that has a thermal component.

Apple mac desktop pictures beach