Sidebar Sidebar
Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.

Macbook Air 2018 USB C AV Adapter Bought from Amazon Issue

A

aj123456

macrumors newbie
Original poster
Nov 30, 2008
15
0
Hello,

I've recently become an owner of a Macbook Air (2018 release). In preparation I had bought a a Travel Inspira 3 in one USB C AV adapter which has a ports for USB C charging, HDMI and USB for connecting Cell Phones and devices to sync.

So far I've tried the USB port to charge a cellphone brick while connected to the Air and it worked perfectly.

I have not tried the HDMI port yet.

However, when trying to connect my Apple charger into the adapter for charging my Macbook Air it would not charge it.

I've tried restarting the computer and tried both USB C ports with the adapter and I still am not getting a charge signal when plugging the power cord in through the adapter to the computer.

Any thoughts or assistance would be great. I'm debating if I should just pony up the money for the Apple adapter but the reviews online for that one seem shaky too.

Here's the link of the adapter I bought: https://www.amazon.com/dp/B01GKSPMCQ/ref=pe_1098610_137716200_cm_rv_eml_rv0_dp
 
As an Amazon Associate, MacRumors earns a commission from qualifying purchases made through links in this post.
Third party adapters are hit and miss and furthermore, new model Macs often pose additional problems for the hub manufacturers.

For example, a lot of fully functional third party USB-C hubs that worked fine with the 2015 and 2016 Macs wouldn’t work properly on the 2017 models for HDMI. Many had to be updated to work with 2017 Macs. Not sure about 2018 Macs.
 
EugW said:
Third party adapters are hit and miss and furthermore, new model Macs often pose additional problems for the hub manufacturers.

For example, a lot of fully functional third party USB-C hubs that worked fine with the 2015 and 2016 Macs wouldn’t work properly on the 2017 models for HDMI. Many had to be updated to work with 2017 Macs. Not sure about 2018 Macs.
Click to expand...

Do you suggest I buy the Apple adapter?
 
I just had this cable matters part arrive today and hooked it up to my new MBA.

I'm running the displayport out directly to a Dell p2715q 27" running 4k.

It works so far in that it gives two USB 2.0 A ports and offers up the other USB C port on the machine. I am tempted to try hooking up the other usbC to the cinema display to see if I can run two monitors off it.
[doublepost=1542070669][/doublepost]I'm not sure, but this accessory may have caused CPU usage from windowserver to spike. I switched back and am going to try to monitor it. But the hub I linked to above may have resulted in more intense resource use.
[doublepost=1542071544][/doublepost]I just found this thread which may explain what happened when I used the dongle I mentioned above.

I can't say for sure, but I don't think I was having any display-related CPU issues prior to trying to use a single USB-C for both power and display. I have had activity monitor opened most of the time and check it fairly regularly to check ram pressure etc. (side note: I'm at 13GB of ram use regularly, I really think it is a mistake to get this new MBA at 8gb!)

This suggests to me it may not be possible to run two external monitors off the new MBA if they can't both benefit from HW acceleration. Experimenting with this dongle caused one of the few "fan events" i've had on this new computer.

https://discussions.apple.com/thread/8417207?answerId=8417207021#8417207021

it is important to understand that what you are asking for (many displays over one USB-C) is usually implemented in a dock with DisplayLink software and a display link chip in the Dock for the second and subsequent displays. These are not "real" displays, in that they have no hardware acceleration and can be slow to update.


DisplayLink software creates a software display buffer in main RAM memory and sends the data out to the external box over a slower than usual connection. Some say these displays are slow. Some users say mouse-tracking on such a display is nauseating, and others have complained that the amount of data for full-motion Video makes these displays unsuitable for that purpose.
Click to expand...
[doublepost=1542072539][/doublepost]I just did a restart and windowserver dropped down to low levels. I am now pretty confident that plugging in that dongle triggered the external display to go into non-hw accelerated display mode.

It is worth mentioning that just switching back from the dongle to the displaymatters straight through usbc -> displayport I'm using did not fix the windowserver process issue. I had to restart.

It may be that if I do a restart with the dongle attached it will read the monitor correctly and not drive up CPU for the display but I haven't tried it yet.

Here's what I normally expect CPU-wise from windowserver on the new mba;
71pTAxt.png


Here's what happened trying that power + video dongle:
Krz0DpM.png


note i had a lot of pycharm work going prior to the restart which is why the cpu was high on that.
 
Last edited:
As an Amazon Associate, MacRumors earns a commission from qualifying purchases made through links in this post.
  • Like
Reactions: EugW
So I went ahead and plugged in the adapter again for power, and instead ran video straight into the MBA's other USBc. This kept the machine from running CPU up. It allows for 2 USB A and a USB C which is not terrible, but I have pretty low expectation about this machine running two monitors.
 
As an Amazon Associate, MacRumors earns a commission from qualifying purchases made through links in this post.
You must log in or register to reply here.
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.
Top Bottom
Back