Updated: June 06, 2023
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by Anna Chernetska
Tech Expert & Writer
712 resolved issues
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Smartphones, Tablets, Apps, 4G/5G issues

I need to replace the time machine backup disk.

I have an iMac 27 inch 2017. It uses USB 3. I have a LaCie USB C disk. Can I use it with an adapter?

Short summary:

  1. Locate the Thunderbolt 3 ports on your iMac.
  2. Plug one end of the USB-C cable (the cable that came with the USB-C disk) into the USB-C port on the disk.
  3. Plug the other end of the USB-C cable into one of the Thunderbolt 3 ports on your iMac.
  4. Ensure that the USB-C disk is powered on and connected to the iMac.
  5. Wait for your iMac to recognize the USB-C disk. It may take a few moments for the disk to appear on your desktop or in Finder.
  6. Once the USB-C disk appears on your iMac, you can access its contents and use it for backups or storage as needed.

Hello, thank you for using Howly.
Please specify what you mean by "time machine backup disk"

Customer Replay

It is a disk that is used by the time machine app
It is a back up disk for automatic backup

Got it, thank you for your information!

Customer Replay

Can I hook up a USB C disk to a USB 3 port?

Top answer

Please be aware that external drives can connect to a USB, Thunderbolt, or FireWire port on the Mac.

Customer Replay

I don't have Thunderbolt or firewire as far as I know, only USB 3
Should I have a Thunderbolt port on this model iMac? I've never noticed it nor used it?
I think USB C is Thunderbolt
The LaCie disk said it was compatible with my iMac when I ordered it but I can't find a way to plug it in.

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Top answer

This model should have - Two Thunderbolt 3 ports
The Thunderbolt port is compatible with USB-C, can you locate the Thunderbolt ports on your machine?

Customer Replay

Do you know where they're located? I don't see any thing but the Usb ports and the disk cord has a different plug.

Here is how they should look like:


Do you see the same ports on your machine?

Customer Replay

I found them. I never used them and didn't know I had them. That should handle my problem. Thanks.

I am glad that I was able to help, *****!

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