Connecting 12" Macbook to Thunderbolt display doesn't work (USB-C to HDMI to Thunderbolt)

Sorry, not an answer, I just want to vent.

I recently purchased a 5K monitor with my new MacBook Pro - all good. Then I was mystified when I plugged in my wife's 2016 MacBook Retina 12"and got a message it was not supported. After hours of research I find Thunderbolt 3 and USB C are incompatible in some instances, this monitor being one of them.

This is the last straw...after many years of being an Apple faithful buying a new set of special cables with each new device, this is the pinnacle of taking the mick.

Matching an external display to a computer has long been a challenge waiting to grab unsuspecting users by the proverbial short-hairs! Now that many computer manufacturers have adopted USB-C ports, there’s been an uptick in reports of mis-match issues such as what you’re describing because the presence of a USB-C port on a device does NOT imply or guaranty what uses that manufacturer chose for it. Apple is not alone in selecting a subset of possible USB-C features and performance -- in this instance -- for inclusion on the MacBook 12" series. Other manufacturers have made similar choices when designing smartphones and tablets which also employ USB-C ports.

Your mention of “Thunderbolt” suggests that is the likely cause of your mis-match, since neither version of the 12” MacBook are Thunderbolt capable — and you won’t find that word used even once in Apple’s MacBook 12” description and tech specs.

However, you may still find a common ground with your (unnamed) 5K display, if it also supports video via HDMI and/or DisplayPort which are supported by 12” MacBooks. You’ll still need to find at least one common resolution and frame rate supported by both devices, and select a good quality adapter and cable — designed to support your selected resolution & frame rate.

Good luck!

Thanks Deltaman, sorry should have said, its the official Apple sponsored LG Ultrafine 5K display. So far I have been unable to find any other ports on it other than the Thunderbolt USB-C ports, though I'm certainly open to any ideas you may have.

Thanks for clarifying. I suspected you were referring to an LG Ultrafine 5K, but hoped this thread might be more useful to others, if it was called-out...

Unfortunately, the rest of the "news" isn't good, as LG made a marketing decision to only support a video connection over Thunderbolt 3 via an included USB-C cable -- which confusingly looks compatible with your 12" MacBook and other devices which lack Thunderbolt tech under-the-hood. I'm not aware of any adapter which would allow using your LG 5K with your wife's MacBook. However, there are several competent 4K displays which are compatible with the 12" MacBook.

On the other hand, Apple's basic 13" MacBook Pro does have Thunderbolt 3 built-in and is a modest price-bump over a 12" MacBook. If you've owned the MacBook only a short time, you might choose to explore your upgrade options with the manager of a nearby Apple retail store...

Good luck!

The present 2015 MacBook 12-inch Retina model does not support the Apple Thunderbolt display

from what I've read. The other Apple Cinema models can work if they are used with correct adapters

as could other brands. Some of the adapters do not support audio, while others do. Note there are

limits to the supported display specifications; this may narrow their usefulness if not best configured.

Special adapters and cables can allow one to configure certain display options for use with MacBook.

The graphic support across MacBook, MacBook Air, MacBook Pro varies along with specifications.

The lack of a Thunderbolt port, use of adapters to supply only what it can support MacBook 12-in.

and the mini-display-port does not connect or transfer at frequencies Thunderbolt displays use. The

cure would have to be built-in support for that; so adapters could carry the signals. A new model

could include such an improvement; but there's nothing of that spec in the Apple Store yet.

• Use 4K displays and Ultra HD TVs with your Mac - Apple Support

• Thunderbolt ports and displays: Frequently asked questions (FAQ) - Apple Support

• Get help with video issues on external displays connected to your Mac - Apple Support

Good luck & happy computing! 🙂

The simple answer is - "You're using it wrong!" That Monoprice adapter is designed to connect a DisplayPort OUTPUT from a computer, to a HDMI INPUT on a display. As you pointed out — it works fine when hooked-up that way. However, that adapter is designed to work in only that one direction, and when you reversed it, to connect FROM a HDMI OUTPUT to a DisplayPort INPUT — it ceased to function. The "good news" (if there is any) is that Monoprice will probably refund your purchace price since they have been giving-out incorrect advice about using that adapter with the MacBook 12"

(Sorry to be th' Messenger! I'm here 'cuz I'm also seeking same solution...)

Of course, the newest MacBook 12-inch Retina has different specifications than the earlier 2015.

And so the peripheral accessories may act differently; while the point you make would appear

valid should an accessory be designed for one useful purpose and support one-way traffic. When

an item cannot negotiate or hand-shake to other devices through such an adapter, then one needs

to locate and test a suitable replacement. Or change the ideas to formulate new plans to so enable.

Thank you for the information on the adapter in first question. My reply indicated one may need to

acquire an adapter from Apple and use their instructions. If the method of use was not included in

their instructions, then it could not be expected to perform in a manner it was not intended.

A newer build model could have a different circuitry path and technologies to allow different usage.

In any event...

Good luck & happy computing! 🙂

The performance enhancements in the 2016 MacBook are quite modest but welcome. However, there are no differences in the specifications of the multipurpose USB-C ports between the 2015 & 2016 models. Apple's "official" position is that there is no supported way to connect the video output of a MacBook Retina 12" to either the Apple Cinema or Thunderbolt Displays.

A Thunderbolt display will only work with a Mac that has a Thunderbolt port. The 12" MacBook does not have a Thunderbolt port. End of story.

(There's been no sign of g-pod returning since that original post...)

A DisplayPort/ThunderBolt to HDMI adapter is NOT the same as an HDMI to DisplayPort adapter. These adapters are only designed to pass audio & video in one direction, so they cannot be used in reverse (as g-pod and several others have attempted). Athough there are HDMI to DisplayPort converters available, they are far more rare and pricey than the cheap and common Display/PortThunderBolt to HDMI adapters. So, although it's technically feasible to hook a MacBook 12" to a ThunderBolt or Cinema Display, you might consider that the extra $200+ you're likely to spend to accomplish that would be better-invested towards the purchase of a new TV or monitor with native support for 4K HDMI...

So, although it's technically feasible to hook a MacBook 12" to a ThunderBolt

No, it is not technically possible to a Thunderbolt Display, to a LED Cinema Display, yes. They aren't the same.

(There's been no sign of g-pod returning since that original post...)

True, but you are the one that started up the post again.

Apple still considers this thread to be active and refers people (including me) to it when they're searching for ways to connect the new MacBooks to external displays, so g-pod's question is still relevant — even tho that person appears to have moved-on without sharing how/if they found a solution...

USB-C and ThunderBolt are similar technologies; they both can support multiple data channels for many of the same modalities thru a single port —i.e. device power & charging, ethernet, audio & video via HDMI & DisplayPort, USB, etc. There are many Web sources which describe how these 2 technologies work, for anybody still feeling unsatisfied after witnessing lots of noisy splashing at the shallow end of the pool. Wikipedia is a good place to start...

so g-pod's question is still relevant — even tho that person appears to have moved-on without sharing how/if they found a solution...

There is no solution for the OP's question. There would be no solution to share. To suggest otherwise, is inappropriate.

Thuderbolt Displays require Thunderbolt ports to operate, "period." Thunderbolts ports will support DisplayPort monitors like the LED Cinema Display, and the physical fit and dimensions of their plugs are the same. But Thunderbolt displays will not work with Displayport outputs or USB-C to DisplayPort adapters.

http://www.apple.com/shop/product/MC914LL/B/apple-thunderbolt-display-27-inch

From above:

Kanex seems to come up with a solution

https://www.kanex.com/thunderbolt3/

but the documentation is weak and the discussion not very helpful yet.

Does anyone have a clue?

The I/O connector on a MacBook 12" employs a USB-C form factor - which can optionally support many different uses. However, physical compatibility does not mean that all those potential uses will be supported by every device that employs a USB-C connector. For instance, the MacBook 12" design uses its USB-C port for charging, USB data, HDMI & DisplayPort; it does NOT support any flavor of ThunderBolt. The referenced Kanex adapter is NOT a converter; it cannot create ThunderBolt output where there is no ThunderBolt input present.