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hbg

macrumors regular
Original poster
Jul 6, 2007
121
2
I want to get an LG ultra fine 5K monitor for my MacBook Pro 2017. On the back of the monitor is the lightning port with power (circled). Normally, you connect this is to the lightning port on the MacBook Pro and it charges the mac in addition to getting video signal for the LG. However, I have a Belkin Thunderbolt 3 docking station that I instead want to connect to my MacBook Pro as it can also provide the MacBook Pro power through the docking station's lightening 3 connection. The docking station has another lightning 3 port to which lightning devices can be connected. Can I connect the LG to that and get video and also not hurt the LG since the LG also provides power through the circle lightning port?


Also, with the above setup would I also be able to connect, at the same time, an Apple Thunderbolt display to the back of the LG 5K monitor using a Thunderbolt 3 to 2 adapter?


My reason for setting it up this way is to have only to make one connection to the MacBook Pro each day at the office. Plus, the combination would give me lots of connections (both through TV, docking station and the back of the Apple Lightning Display).
 
Can I connect the LG to that and get video and also not hurt the LG since the LG also provides power through the circle lightning port?
Yes, this is fine. The LG display will cease providing power and the Belkin Thunderbolt 3 dock will charge your MacBook Pro instead.

Also, with the above setup would I also be able to connect, at the same time, an Apple Thunderbolt display to the back of the LG 5K monitor using a Thunderbolt 3 to 2 adapter?
No. The rest of the ports on the LG display are USB-C ports. They are not Thunderbolt 3 ports, and they do not pass through video.
 
Yes, this is fine. The LG display will cease providing power and the Belkin Thunderbolt 3 dock will charge your MacBook Pro instead.


No. The rest of the ports on the LG display are USB-C ports. They are not Thunderbolt 3 ports, and they do not pass through video.
Yes, this is fine. The LG display will cease providing power and the Belkin Thunderbolt 3 dock will charge your MacBook Pro instead.


No. The rest of the ports on the LG display are USB-C ports. They are not Thunderbolt 3 ports, and they do not pass through video.

Thanks much. So, am I right that there is no way to use both the LG monitor and the Apple Thunderbolt display without having them both connected directly to the Mac?
 
Thanks much. So, am I right that there is no way to use both the LG monitor and the Apple Thunderbolt display without having them both connected directly to the Mac?
That is correct. The LG 5K saturates the Thunderbolt 3 connection. There is no bandwidth left (or, more accurately and technically, there are no more 'DisplayPort lanes' available) for any extra video.

You didn't mention whether you had a 13" or 15" MacBook Pro. If you have a 13", then one 5K display is all it can support, regardless of whether both displays are connected directly to the Mac or not.

If you have a 15" MacBook Pro, then you can do it with the Thunderbolt 3 to Thunderbolt 2 adapter. Each cable must be connected to opposite sides of the MacBook because each side only has one display driver.
 
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Yes. I do have the 3 to 2 adapter and I do have the 15". Thanks for all of this and the driver clarification- you've been really helpful. I wish there were some way to only use one connection to the Mac...
 
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