iMac 2017 27-inch Retina 5K won't boot up and runs slowly.

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Level 1

27 points

iMac 2017 27-inch Retina 5K won't boot up and runs slowly.

iMac 2017 27" Retina 5K won't boot up. When I turn it on, it begins but I got an error report which I took (5) pictures of with my phone because it wouldn't let me copy and paste. It's running below a snails pace. Prior to this, it was running fine, I shut it down as I was going to be away for 4 days. Came back to this problem 4 days later. No power outage during our absence. I have unplugged external hard drives that are usually plugged into iMac. Nothing attached currently except wired keyboard (came from my old 2009 iMac) which has a plug on keyboard for wired Apple mouse.

Model: 18,3 3.4GHz Quad-Core Intel Core i5, 16GB 2400MHz DDR4, Radeon Pro 570 4GB.

iMac 27″ 5K, macOS 13.7

Posted on Aug 19, 2026 5:38 AM

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Answer 1

Top-ranking reply

den.thed

Level 10

96,852 points

Aug 19, 2026 6:55 AM in response to CynicChick

Post a couple of those images that you took with your iPhone.

Startup the iMac in Safe Mode, sign in and let it run for 20 minutes, then Restart.

see > Start up your Mac in safe mode - Apple Support

Download and run the free version of EtreCheckPro, from > https://etrecheck.com/en/index.html

Then post back here with your Report, as per > How to use the Add Text Feature When Post… - Apple Community

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Answer 2

den.thed

Level 10

96,852 points

Aug 19, 2026 11:02 AM in response to CynicChick

Does it startup in Safe Mode…?

If not…? It sounds like the hard drive is failing or failed and the iMac needs to be checked out by an Apple Store or Authorized Service Provider.

https://getsupport.apple.com/locations

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Answer 3

ckuan

Level 10

121,430 points

Aug 19, 2026 5:47 AM in response to CynicChick

Try running EtreCheck and post result here

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Answer 4

KiltedTim

Level 10

235,766 points

Aug 19, 2026 10:58 AM in response to CynicChick

I I had to guess, I'd say your hard drive is undergoing a catastrophic failure.

It's time for a new machine. Even a cheap external drive would cost more than that machine is worth now.

Hopefully, you use Time Machine or another backup system and an external hard drive to back up your data.

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Answer 5

CynicChick Author

Level 1

27 points

Aug 19, 2026 10:30 AM in response to CynicChick

If this program needs to be downloaded and run from my iMac, it's too slow to do so. I mean I wait forever for it to boot up and it doesn't finish. I'll try to upload the 5 pics I took of the Error Report it supposedly was sending to Apple who won't care about a 2017 iMac that is not under warranty.

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Answer 6

CynicChick Author

Level 1

27 points

Aug 19, 2026 10:46 AM in response to CynicChick

Tried to download it. I can't open Safari. Mouse first froze, then spinning wheel. When that stopped I tried to open Safari again. It bounced in the dock for a short while then stopped. Now nothing.

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