Thunderbolt not working after upgrade to Yosemite

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Level 1

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Thunderbolt not working after upgrade to Yosemite

Did a clean install of Yosemite on Friday 10/17 and after install my Thunderbolt backup drive is no longer accessible. If I switch it and use the USB base for the drive and plug the drive into a USB hub it immediately gets picked up and is usable and works with Time Machine.

I then did a clean install of Yosemite on my MacBook Pro that I purchased 2 months ago. I first connected the backup drive to the MBP via Thunderbolt and did a backup. I disconnected the drive and then did the clean install. Afterwards I reconnected the drive via Thunderbolt to the MBP and it immediately recognized it. ???

I purchased my 27" iMac in February 2013 and Thunderbolt has been working fine since the day I got it. Now though, it's not working at all.

I have found on here that several people are having problems with Thunderbolt since upgrading to Yosemite but seems no one has found a solution yet.

Any suggestions?

TIA!!

Posted on Oct 19, 2014 7:18 AM

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Answer 1

pedro d

Community Specialist

Oct 22, 2014 6:49 AM in response to Rathius

Hello there, Rathius.

The following Knowledge Base article offers up some great recommenddations for troubleshooting issues with a Thunderbolt device not working:

OS X Yosemite: If a Thunderbolt device isn’t working

If your Thunderbolt device isn’t working, try any of the following suggestions:

Check the device: Make sure the device is turned on and its cables are connected. If the device requires a power cord, make sure it’s plugged in. If the device is in a chain of devices, remove the device from the chain, then plug it directly into your computer and verify that it works.

Check that you’re using the right cable: Make sure you connect the Thunderbolt device with a Thunderbolt cable, and not a Mini DisplayPort cable. A Thunderbolt cable has a Thunderbolt icon on the connector.

Check for missing software: Make sure you installed any software that came with the device. Check the manufacturer’s website for the latest software.

Check chained devices: If the device is in a chain of connected Thunderbolt devices, each connected to another with only one connected directly to the Thunderbolt port , disconnect the device from the chain and verify that it works (see Check the device, above). Then make sure that all the devices other than the one connected directly to your Mac have power cords. (If the device connected directly to your Mac requires a power cord, it should have one, too.) If a Mini DisplayPort device is part of the chain, make sure it’s at the end and is connected with a Mini DisplayPort cable.

Verify that the device appears in System Information: Choose Apple menu > About This Mac. In the window that appears, click Overview, then click the System Report button to open System Information. Open System Information for meIn the window that appears, see if the Thunderbolt device is listed below Hardware in the Contents list. If the device appears but does not work, review the device’s documentation for further troubleshooting steps.

Restart apps: Quit and restart any apps that use the device.

Restart your Mac: Choose Apple menu > Restart.

If these suggestions don’t work, see the documentation that came with the device for troubleshooting tips, or contact the manufacturer for help.

About Thunderbolt

Check your device’s Thunderbolt connection

Thanks for reaching out to Apple Support Communities.

Cheers,

Pedro.

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Answer 2

hilo2275

Level 1

9 points

Nov 1, 2014 4:30 PM in response to pedro d

Hi Pedro,

I have a 2011 iMac and a 2011 Mac Mini. I purchased a new external Thunderbolt hard drive, backed up and did a clean install of Yosemite on the iMac first. The new HD would not stay mounted on the Thunderbolt port but did stay mounted via USB to get the backup done. Even after a clean install the drive kept ejecting itself on the Thunderbolt port. On the Mac Mini the drive does not even power on in the Thunderbolt port but powers on and mounts just fine via USB. I haven't attempted the clean install on the Mac Mini yet because I really want to use the Thunderbolt port for the backup. I've already replaced the power adapter on the new HD. The problem persists. What do you think is going on?

hilo

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Answer 3

Rathius Author

Level 1

0 points

Nov 2, 2014 2:45 PM in response to hilo2275

@hilo2275 Basically your Thunderbolt ports are Thunderbolt 1.0 and Yosemite mainly supports Thunderbolt 2.0 (this is what I was told by an Apple tech). What has to be done is a new driver installed from the drive manufacturer. When I did that, I no longer had any issues.

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Answer 4

hilo2275

Level 1

9 points

Nov 3, 2014 5:47 PM in response to Rathius

Hi Rathius,

Unfortunately that's not an option with G-Tech. They had me reset SMC and PRAM and now the drive won't mount at all on the Thunderbolt port, but still works just fine on the USB port. G-Tech said I'll need to ask Apple how to do a firmware update for the Thunderbolt controller. Guess I'll have to keep my Genius Bar appointment tomorrow afternoon and find out whether it's a firmware issue or a bad Thunderbolt port on the brand new HD.

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