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

Wowfunhappy

macrumors 68000
Original poster
Mar 12, 2019
1,822
2,115
I'm a teacher, and I'm working in a new school this year! The school gives all teachers a 13" M1 Macbook Air to use in their classrooms. But I don't want to use their computer, I want to use my 11" 2014 Macbook Air which I know and love.

All classrooms are equipped with USB-C cables. You can plug these USB-C cables into an M1 Mac to display content on the projector. Behind the scenes, the projector appears to be using HDMI input, so somewhere in the walls the USB-C signal is getting converted to HDMI, but I have no ability to mess with this. I need to use this USB-C cable.

My 2014 Macbook Air uses Mini DisplayPort for video output. I need an adapter (or adapters) to get from my laptop's Mini DisplayPort to the school's USB-C cable. I have tried:

1. Cable Matters Bidirectional Mini DisplayPort to USB C Cable + Poyiccot USB C Female to Female Adapter

2. Cable Matters Mini DisplayPort to DisplayPort cable + WJESOG DisplayPort to USB C Cable + Poyiccot USB C Female to Female Adapter

(The USB-C coupler is the same for both, it's so simple I find it hard to believe it's the problem. Also, an LED on the coupler lights up when both ends are plugged in, making me think it's working.)

Neither of these combinations worked! Both the laptop and the projector say that nothing is plugged in.

Any ideas how I can make this work?
 
As an Amazon Associate, MacRumors earns a commission from qualifying purchases made through links in this post.
USB-C is a mess: HDMI-alt mode and DisplayPort alt-mode are both passive. I don't think HDMI-alt mode is actually used much though, so if your projector is ultimately accepting hdmi input then there is an active conversion from displayport to hdmi happening somewhere.

Regardless, unidirectional cables will not work for you, you need a bidirectional cable. This should still be a passive connector, but the cables are apparently hard to find and like all things usb-c mislabeling abounds.

The wacom link plus seems like a solid product, although it's slightly stronger than what you need since it supports active hdmi -> usb-c displayport conversion.

Some products are tested in

and in
 
Last edited:
  • Like
Reactions: Amethyst1
The wacom link plus seems like a solid product, although it's slightly stronger than what you need since it supports active hdmi -> usb-c displayport conversion.
Its HDMI port is only 1.4. For HDMI 2.x to USB-C DP Alt Mode, there are cheaper and more capable alternatives.
 
Last edited:
  • Like
Reactions: TheShortTimer
I want to use my 11" 2014 Macbook Air which I know and love.

You could mirror the MacBook Air if the monitor has the capability and that MBA is running Catalina to current.
I did that with a MBPro 13" 2012 to a neighbors' TV this march without any problems.
what helped was a airport base near both the MBP and monitor.


ii hoped this helped, if no the HDMI dongle will work as well
 
  • Like
Reactions: _Mitchan1999
You could mirror the MacBook Air if the monitor has the capability and that MBA is running Catalina to current.
I did that with a MBPro 13" 2012 to a neighbors' TV this march without any problems.
what helped was a airport base near both the MBP and monitor.
It's a good thought, but it won't work because (A) my Macbook Air runs 10.9, and there is some sort of AirPlay incompatibility between that OS and anything modern, and (B) the school's wifi network is too locked down. (Specifically, wifi client isolation appears to be enabled.)

Try a Wacom Link Plus. I‘ve successfully used one to connect my USB-C-only LG UltraFine 4K to various (mini)DisplayPort sources, the oldest being a 2008 MacBook Pro. No need for the USB-C coupler either then.
The Wacam Link Plus appears to have been discontinued, it's out of stock everywhere! (Your link is to Wacam's Australian store, I'm in the United States.) There are some on eBay, but I'm nervous because, given how much this costs, I want to be able to easily return it if it doesn't work.

Regardless, unidirectional cables will not work for you, you need a bidirectional cable
The first combination I tried was with a cable listed as bidirectional. The second combination had a unidirectional cable, but in the right direction (see how there's actually a USB-A input on the DisplayPort end).

Thanks! Everything under DisplayPort → USB-C is out of stock except for the MonoPrice and Startech ones, but I guess I can try MonoPrice next? It's just that after two failed attempts, I'm a bit nervous about continuing the strategy of trying random things, but I guess it's all I can do...

Edit: But a bunch of the Amazon reviews for the MonoPrice and Startech cables say it's actually unidirectional, uggh!
 
Last edited:
  • Like
Reactions: Amethyst1
Try OWC they have everything!
I took a look through the store and I can't seem to find anything for this case, do you have a recommendation?

---

For now, I ordered a Wacom DisplayLink on eBay. I figure that since passive converters haven't worked, I really need to try an active one, overkill or not. And although it's expensive, I consider this a professional expense.
 
Last edited:
> But a bunch of the Amazon reviews for the MonoPrice and Startech cables say it's actually unidirectional, uggh!

Yeah unfortunately usb-c is a crapshoot. It's hard to sort out whether the cables are legit and people are using it mistakenly (e.g. maybe they need hdmi alt-mode instead of DP-alt mode, or maybe they need one that also delivers power) or whether the cable itself is just bad.

The Wacom DisplayLink should work, every review I've seen of it seems to indicate it works for pretty much every combination you can throw at it.
 
It's a good thought, but it won't work because (A) my Macbook Air runs 10.9, and there is some sort of AirPlay incompatibility between that OS and anything modern, and (B) the school's network is too locked down.
Is there a particular reason you are still running 10.9? The machine you are using will need to conform to certain requirements in order to run their institutional software. It’s unlikely they will allow such an outdated vulnerable OS in such an environment. I know it might seem inconvenient now, but save yourself a headache later and take the M1. Those USB-C cables in the classrooms may be coming from a hub that supports power delivery as well.
 
Last edited:
I have this one, but didn't use it to connect a display. Don't know if that might work. I think you need a least a TB1 or 2 cable instead of miniDP. Is DP included in TB? Or only same connector? I don't know.


IMG_0029.jpeg

Edit: Only supports Thuderbolt-Displays.

"Note: This adapter does not support DisplayPort displays like the Apple LED Cinema Display or third-party DisplayPort and Mini DisplayPort displays. For more information, visit the Apple Support page for the Thunderbolt 3 (USB-C) to Thunderbolt 2 Adapter."

USB isn't even mentioned there. Only as port type, but not display protocol.

 
Last edited:
The Wacam Link Plus appears to have been discontinued, it's out of stock everywhere! […]
I no longer need mine and would be willing to let go of it. Shipping from Europe to the US would still apply though.

Try OWC they have everything!
Not in this case. ;)

For now, I ordered a Wacom DisplayLink on eBay.
You mean a Wacom Link Plus? (There is also a Wacom Link-without-Plus; I have no experience with that.)

Nope, HDMI was they way to go back then, anf today as well!
DisplayPort is better: more bandwidth, more features, no outrageous licensing fees. ;)

The Wacom DisplayLink should work, every review I've seen of it seems to indicate it works for pretty much every combination you can throw at it.
My experience confirms that. One setup that didn’t work was feeding it the DP input from a dual-link DVI to DP converter.

I have this one, but didn't use it to connect a display.
As you added, that won’t work unless the display requires Thunderbolt input.

USB isn't even mentioned there. Only as port type, but not display protocol.
The USB-C bit should be dropped from the adapter’s description altogether because it neither allows USB-C devices to be connected to TB1/TB2 hosts, nor vice versa. That bit just creates confusion.

Is DP included in TB?
Yes. Doesn’t matter in this case because USB-C DP Alt Mode is what’s needed.

Update: We‘ve since discovered we‘re actually dealing with a Thunderbolt 3 dock here which does require Thunderbolt video input.
 
Last edited:
Yes, they often do but the prices are always astronomical compared to other places.
Okay I will bite back!

but OWC has much better quality which is better since the part will last longer than a hack amazon vendor.
I went cheap in 2018 an everything from amazon broke that year, on lightning connector frayed inside my iPad in 2020 and I needed to replace the port for 129$
I still have OWC parts from 2006 even a spinning drive from 2009.

Their batteries are their what we should spend the extra on if we like our early Intels as my MBA 2010 air new battery lasts longer hour wise than the  one and that ssd blade is faster than the original drives.

while i- fixit over charges by 25% on every part since they know humans are lazy and desperate to look elsewhere..

when I raced bicycles, I always purchased the better part so I can finish the course as others did not.
if we think are MacBooks and Mac are that important we should pay extra for better parts that last and wont break.
 
but OWC has much better quality which is better since the part will last longer than a hack amazon vendor.
... which must be why OWC SSDs never fail. :D

and that ssd blade is faster than the original drives.
The original Toshiba HG3 blade isn't great, so it's easy to beat. Some 2010 (and later, 2011) MBAs got Samsung 470 blades which are quite a bit faster.

if we think are MacBooks and Mac are that important we should pay extra for better parts that last and wont break.
Absolutely, but OWC isn't the only kid in town.

I still have OWC parts from 2006 even a spinning drive from 2009.
OWC never made HDDs.
 
Last edited:
You mean a Wacom Link Plus? (There is also a Wacom Link-without-Plus; I have no experience with that.)
Oops—yes! (Where did "DisplayLink" come from? I double checked and the product I ordered on eBay definitely says "Wacom Link Plus".)

I no longer need mine and would be willing to let go of it. Shipping from Europe to the US would still apply though.
I really appreciate that! I've already ordered one from eBay now, though. :) Once it arrives, I will report back!

I'm gonna be that guy and ask: why not just use their M1 MBA? It's not like there's a radical difference in the form factor between that and your 11" MBA.
Is there a particular reason you are still running 10.9? The machine you are using will need to conform to certain requirements in order to run their institutional software. It’s unlikely they will allow such an outdated vulnerable OS in such an environment. I know it might seem inconvenient now, but save yourself a headache later and take the M1.
I have done a lot of work to keep 10.9 working. But to be clear, I'm keeping the school's M1 Macbook Air under my desk and I will always have it as a backup. My preference for Mavericks will never affect my ability to do my job.

However, I also genuinely believe my Mavericks laptop will be more reliable for me. Mavericks never changes, it never has new bugs, and I know exactly where all the sharp edges are. If there is one thing in life that makes my blood boil, it is when I am in the middle of a lesson and my technology decides to mess up. I want to use a system I set up which I know and trust.

As an aside, I don't have admin access to the school laptop. I am a technical person and I want to have a command line available that has a C compiler and Docker and stuff.
 
Last edited:
Okay I will bite back!

mgm-maitredj.gif


:D

but OWC has much better quality which is better since the part will last longer than a hack amazon vendor.
I went cheap in 2018 an everything from amazon broke that year, on lightning connector frayed inside my iPad in 2020 and I needed to replace the port for 129$

The flex on my original MagSafe adapter for my 2006 MBP burned away right in front of me - this was fortunate in the sense that had I been asleep, the consequences could have been dreadful. This was a product that had been included with a computer that when brand new, cost the better part of £2,000 GBP. Hardly cheap and look what happened there.

When I complained to Apple's representatives on the phone and in person, although the MagSafe adapter was replaced, their attitude to was a blatant fire hazard and health and safety issue was appalling. In contrast, the relatively cheapo 3rd party adapter that I purchased for my iBook G3, contrary to the online hysteria and scaremongering, hasn't exploded or caught fire.

Of course, paying a pittance can often lead to paying more in the long run but that's not always a given.

I still have OWC parts from 2006 even a spinning drive from 2009.

Ok. I have an HDD from the mid 90s that still works and it didn't involve paying a premium for the OWC label. As @Amethyst1 pointed out, OWC don't manufacturer the drives themselves. They're just re-badged units which are then marketed with an assurance of quality at a premium.

On that subject...

Their batteries are their what we should spend the extra on if we like our early Intels as my MBA 2010 air new battery lasts longer hour wise than the  one and that ssd blade is faster than the original drives.

There are numerous posts - some within this very forum (here's a thread in which you were a participant ;) ) reviews and blogs written by people who bought OWC batteries and found them to be overpriced lemons that often failed after 12 months and lasted at best for 24 months.

As for the SSD blade, @Amethyst1 covered this in his reply, so I'll just add that through the decades Apple has typically equipped their computers with underperforming drives - 4200 RPM on the iBook G4 instead of 5400 RPM and on the Intel range, 5400 RPM instead of 7200 RPM quite frequently.

Under those circumstances, anyone can do better - including the consumer. As you know - because you contributed to the thread, I replaced the stock 64GB SSD in my 2010 MBA with a 256 GB unit and it cost me far less than a similar offering from either Apple or OWC.

while i- fixit over charges by 25% on every part since they know humans are lazy and desperate to look elsewhere..

Yes - whilst OWC overcharges with re-badged products that from the amount of disgruntled consumers I've come across, often fail to live up to the premium that's exacted or the promise of longevity.

when I raced bicycles, I always purchased the better part so I can finish the course as others did not.
if we think are MacBooks and Mac are that important we should pay extra for better parts that last and wont break.

Quite so - but OWC's products often have an equally poor life expectancy and people just pay all the more for that disappointment.
 
Last edited:
As an Amazon Associate, MacRumors earns a commission from qualifying purchases made through links in this post.
It sounds like a security risk for the school network, connecting an unsupported and unpatched OS.
 
It sounds like a security risk for the school network, connecting an unsupported and unpatched OS.
The wifi network I'm using isolates clients, so this is really no different from using an old computer at Starbucks. (Even if it didn't, I really don't see how you could do damage.) Note that students bring in their own laptops too!
 
Last edited:
The network isolates clients, so this is really no different from using an old computer at Starbucks.
Depends on your school network, where I work people get fired if they put unsupported and unpatched devices. Check with your school network and admins.
 
  • Wow
Reactions: Slix
Welp, after going through eBay shipping hell for a couple weeks (product clearly listed as shipping from the United States shipped from China instead, I'm pretty annoyed with the seller), the Wacom Link Plus arrived Friday evening.

I actually came into school on Saturday because I wanted to test it (and I was in the area). Hook it up and... still nothing! Projector says there is no signal, Macbook Air doesn't seem to recognize anything is plugged into the Mini Displayport.

My M1 Macbook Air continues to display fine.

I'm.... really stumped at this point? What could cause this?
 
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.