Do I need all the cords?

Question

Do I need all the cords?

Hi all! I have a Cinema Display I got in 2009 (apparently designed in 2005) and a Macbook from 2008. The Cinema Display instructions say to connect its DVI, Firewire, and USB cables to the Macbook, and that is what I have been doing. Just now I needed to free up a "full power" USB slot, so I wanted to see what would happen if I used only the DVI connection with the Cinema Display ... and it seems to work just fine. I would love to have that USB slot freed up - is there any reason to have the Cinema display hooked up with all three cables, or is the DVI connection really sufficient?

Thank you, truly, for any information!

- BH

Apple Cinema Display (20-inch DVI 2005)

Posted on Sep 9, 2012 3:26 PM

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Answer 1

Sep 12, 2012 6:10 PM in response to Border Heeler

It should both sync and charge with display USB ports and, if your computer is new enough, with keyboard USB ports. My iPhone syncs and charges from the aluminum keyboard on my 2008 Mac Pro.

(When a recent Mac detects a keyboard with iPhone connected it boosts the USB power on the computer's USB port so the keyboard has extra power to give a full 500 ma to the iPhone.)

Have you tried other USB devices plugged into the display?

Have you tried the iPhone connected without the Mophie case?

Have you tried it with the Mophie switch in both positions?

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Answer 2

Sep 9, 2012 5:45 PM in response to Border Heeler

The FireWire cable is just for the dispay's FireWire ports. If you don't use them you don't have to connect the cable.

The USB cable is needed for the display's USB ports and to allow the computer to control the brightness. The display's USB ports should provide full USB poer (500 ma).

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Answer 3

Sep 10, 2012 9:13 AM in response to Malcolm J. Rayfield

Thank you so much, Malcolm. This answered all my questions. I will plug the USB cable back in and switch my other device (an iPhone with a Mophie battery case - which would sync using the keyboard USB port, but not charge) to the display USB port. It is great to know that the display brightness controls would be affected by not having the USB plugged in. Thank you again!

- BH

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Answer 4

Sep 11, 2012 3:49 PM in response to Malcolm J. Rayfield

I do have a follow-up question. I made the changes I stated above - plugged the display's USB cord in to the Macbook, and then plugged the iPhone + Mophie battery case into the display - and, while the iPhone + battery is now charging, it is not syncing. When I plugged the phone + battery into the keyboard, the opposite occurred: it would sync but not charge (and would give me the low-power-we-are-turning-off-your-device warning). Is this what you would expect: that the phone would not sync when plugged into the display, even though the display's USB cord is plugged into the Macbook?

Thank you!

- BH

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Answer 5

Sep 30, 2012 3:12 PM in response to Malcolm J. Rayfield

Thank you for the reply, and please accept my apologies for my delayed response. I developed a new, more serious problem with my displays (in another thread), so I decided to sync my iPhone via wifi and iCloud and charge it away from the computer until I get the display problem sorted out. If I get that fixed, I will do the experimenting you suggest. Thanks again.

- BH

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