iMac (late 2009) 27 inch display goes black

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iMac (late 2009) 27 inch display goes black

Hello,

I have a late 2009 iMac 27" where after about 20 mins to half an hour, the display goes black. The computer is still running, but to progress any further I have to do a hard shut off and then reboot. Then the same thing happens again later.

I've recently deleted the entire hard disk and done a clean fresh install of HIGH SIERRA thinking that perhaps the screen going black might be software related. Unfortunately it still does it.

Could it be that the graphics card is no longer functioning properly?

Your help and advice is most welcome. Thank you.

Dan

iMac 21.5″, macOS 10.14

Posted on Apr 25, 2021 5:53 AM

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Answer 1

Top-ranking reply

den.thed

Level 10

82,564 points

Apr 25, 2021 7:13 AM in response to Dan Farrell

To check the GPU, connect an external display or put a flash light up to the display panel.

If the external display works or you can see your desktop with a flashlight.

Then the GPU is working and sounds more like a hardware issue with the display panel back-lighting, backlight inverter board or cabling.

Sadly because it it considered obsolete, Apple and many AASPs will not work on it. Plus given it age, it is probably best to replace the iMac then it is to spend a lot of money attempting to repair it.

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Answer 2

a brody

Level 10

84,055 points

Apr 25, 2021 7:01 AM in response to Dan Farrell

yes, and if your Apple menu -> System Preferences -> Energy Saver and Desktop Screen Saver aren't set to go off automatically, the machine may be overheating. Bring it in for service. It probably will cost more than just replacing it with another used Mac of the same vintage. I've seen them go for as little as $150. If running older applications is essential, you'll want to make sure whomever sells you such Mac has recently changed the hard drive, since many go by this point in time, has replaced the CMOS battery if there is one, and is Apple Certified. Otherwise, you will want to consider what it costs to upgrade.

Both http://www.macsales.com/ and http://www.dvwarehouse.com/ offer excellent deals on refurbished Macs.