16" M3 Max MacBook Pro (A2991) & 27" Apple Cinema Display (A1316) not connecting

NucMed wrote:

The Q arises, quite apart from my inability to get the the two devices to communicate (and this is perhaps the most important part of the OP) because of various comments/discussions/rumours on here (Apple support forums) and other external forums regarding these specific devices (> Nov 2023 M3 Max MacBook Pro A2991 running 14.x & earlier monitors including, but not limited to the 27" Apple Cinema Display A1316), positing that there has been some change in the OS/FW or in the actual hardware of the A2991 model that locks out/disables the ability of these monitors to work with this specific iteration of these MacBook Pro.

What "resolution" am I looking for? I am looking for someone who has had hands-on experience/direct knowledge of this specific problem and whether it is soluble or confirmation of the possibility of connecting the two devices has been disabled/locked out by changes to the OS/FW/HW.

I don't have the hardware in question, and can't test it for you. This is a user-to-user forum, and I don't know when or if another user with your specific configuration, who feels like answering. your question, will come along.

All I can say is that when people post on these boards about connecting a 27" Apple LED Cinema Display or a 27" Thunderbolt Display, the usual problems have to do with identifying the display correctly, and then choosing the appropriate adapter.

NucMed wrote:

"A1306 display"

Unsure quite what a A1306 Mini DisplayPort to Dual-Link DVI Video Adapter has to do with this ...

Looks like "A1306 display" has a one-character typo. The 27" LED Cinema Display has model number A1316 – and it's clear to me that Mr. Bennet-Alder intended to refer to that display.

And yet, here we are because using a Mini Display Port to USB-C adaptor to connect my (new) 16" M3 Max MacBook Pro (A2991) to my (old) 27" Apple Cinema Display (A1316), doesn't work.

You may be having trouble with one or more of those three devices (computer, adapter, display).

Hard to know which, but it is good to know that you're using an adapter that is supposed to output a DP signal with a monitor that expects one.

In many other threads on these boards, the problem that people had was use of an adapter that could not offer the right kind of signal. Correcting that usually fixes the problem. So it does not make sense to go into a lot of detailed troubleshooting of other possibilities until this common cause of problems is ruled out.

You say that the monitor works with other Macs, including one which does not have Thunderbolt. So maybe we need to experiment to try to see if there is a fault with the Mac or with the adapter cable.

• Try using the USB-C (DP) to Mini DisplayPort cable with all three of the MBP's USB-C (Thunderbolt 4) ports. You should be able to connect to any of them and get a USB-C (DisplayPort) signal. If you get a signal from some ports, and not from others, that would suggest an issue with the MBP that would warrant having Apple look at it. In that event, you'd want to tell Apple which ports did and did not work.
• If the adapter cable does not work with any of the MBP's three USB-C (Thunderbolt 4) ports, that might point towards the adapter cable being defective.
• You can also Use Apple Diagnostics to test your Mac - Apple Support . I won't guarantee that if there is some problem, that the diagnostics will catch it, but it would be one more way of trying to pin down the problem. A clean self-test run combined with the cable not working on any port would really make me suspect the cable.

Hi guys I have MBP M3 pro chip it connected to apple 27 thunderbult display it works flawlessly , but need 2 adapter 1) apple type c to thunderbolt adapter ( it's called thunderbolt type 3 to 2 ). 2) adapter from mega safe 1/2 to type C. good luck

NucMed wrote:

As an aside, from what you [Hejar1] are saying, it sounds as if the Apple Thunderbolt Display model nr A1407 didn't work unless the MagSafe connector was also attached via an adaptor to a second USB-C port (and I assume, regardless of a charger already being attached to MacBook Pro)? Is that the correct interpretation of what you've written?

The Thunderbolt Display, and other old Apple displays that offer MagSafe 1 or MagSafe 2 power, don't care if you ignore their power offerings. You can leave the MagSafe 1 or 2 plug unused, as long as you don't "short" it out – and the video connection will work just fine.

I know of no adapters that go from MagSafe 1 or 2 to MagSafe 3, and assumed that there would likewise be no adapters to go from MagSafe 1 or 2 to USB-C (Power Delivery). Thus Hejar1's report that he is using an adapter that does exactly that was a surprise to me. A search turned up at least one out there.

So you could power a modern Mac notebook using one of those old displays, but I'm not sure it would be worth it. You would be using two USB-C ports: one to carry a DisplayPort or Thunderbolt signal to the old display; another to carry MagSafe 1/2 power from the display and the MagSafe 1/2 to USB-C adapter to the notebook. Might as well use the USB-C Power Adapter and USB-C to MagSafe 3 charging cable you already have.

If so, I wonder whether that may also be the problem with the 27" Apple Cinema Display A1316 not connecting, requiring, not just mains power to the monitor, as well mains power via the charger to the MacBook Pro, but also a power connection via the monitor's MagSafe connector via a USB-C adaptor ... it seems a bizarre requirement to lose 2 USB-C (of 3) ports to run a monitor (insert eyeroll & shrug emojis here) ...

It's not a requirement.

• If you were using a modern monitor that took USB-C (DisplayPort) or Thunderbolt 3/4 input, the same USB-C cable or Thunderbolt cable that carried video to the monitor could carry power back to the notebook.
• If you are using one of these old Apple displays, it makes sense to ignore the power from the old display, and just keep using power from another source (such as the USB-C Power Adapter and the USB-C to MagSafe 3 cable that came with your M3 Max MacBook Pro).

It's unfortunate that there seems to be no male HDMI to female Mini Display Port or Thunderbolt cable/adaptor method to connect direct to the HDMI port on the M3 MacBookPro so a USB-C port is not wasted.

There are several unidirectional, active adapters that have a HDMI plug (to be connected to a video source), and that provide a full-size DisplayPort plug or socket (for connecting a monitor). Finding them (I looked on Amazon) is a bit like finding a needle in a haystack, but they are out there.

The catch with many is that they are "power-sucking aliens". You have to plug in a short, attached USB-A cable, so they can suck electrical power from one of your USB-A (or USB-C) ports. That would defeat the purpose that you are trying to achieve.

FYI, there is no adapter that will go from a HDMI port on a computer to any version of Thunderbolt. Thunderbolt is a bit like an extension of PCIe outside of a computer box. You can get lots of PCIe video cards (for PCs) that have HDMI outputs. That doesn't mean that you can build a box with a bunch of PCIe expansion slots and hook it up to a notebook computer via the notebook computer's HDM port.

NucMed wrote:

I remain baffled why Apple did not make either an HDMI to Mini Display Port adaptor or a USB-C to Mini Display Port adaptor (they obviously though it worthwhile to make the Apple MMEL2AM/A Thunderbolt 3/USB-C to Thunderbolt 2 adaptor) and left it to outside companies (perhaps without the same levels of QC & GMP assurance to manufacture them).

Based on the number of third-party adapters I see, it looks like

• The third-party market has USB-C(DP) to (DP, mDP, HDMI, single-link DVI, VGA) well-covered. There are even a few active USB-C (DP) to dual-link DVI adapters for people with old 30" 2560x1600 pixel Cinema Displays.
• The third-party market overwhelmingly favors USB-C(DP) to HDMI and (m)DP to HDMI adapters over those that go in the opposite direction. There may not be a large market for HDMI to (m)DP conversion out there. Almost all of the HDMI to DP adapters I found had the disadvantage of being "power sucking aliens" that needed a USB connection for power (which in your case, would have negated the whole reason for using such an adapter).

Thus Apple could leave that stuff to the third-party market.

The Thunderbolt 3-to-2 adapter is a different story. Few, if any, third-party suppliers make those.

Here's one. It's over twice the price of the Apple adapter, and it's unidirectional (which means that it is not as functional as the Apple adapter). It has the same limitation as the Apple adapter with regards to not providing plain DisplayPort signals on the Thunderbolt 2 side. The description also says "This adapter is not compatible with Thunderbolt 4 computers." Happy, happy, joy, joy!

https://www.amazon.com/StarTech-com-Thunderbolt-Adapter-DisplayPort-TBT3TBTADAP/dp/B019FPJDQ2/?th=1

also look at:

 menu >about this Mac > (System Report) > Hardware > Graphics&Displays

My setup is differnt, but IF the display hardware is being seen by the Mac it should be listed in a comparable way:

...

That restriction only applies when you are streaming HDCP protected content. Everything else displays just fine.

I skimmed your post, but could not find how you are connecting the 16" M3 Max MBP to the 27" Apple Cinema Display (A1316).

I assume that you have verified that it is indeed a 27" Apple LED Cinema Display, not a 27" Thunderbolt one. That is, it has model number A1316, has a USB-A upstream connector, and does not have FireWire 800 or Ethernet hub ports. The fact that the display works with your 17" mid-2010 MBP strongly suggests that you have the LED Cinema Display. That MBP predates, and lacks, Thunderbolt.

You will need a USB-C (DP) to Mini DisplayPort adapter. The Apple Thunderbolt 3-to-2 adapter only translates Thunderbolt, and won't work to drive a Mini DisplayPort display plugged directly into its TB2 side.

To control the brightness of the monitor from the MBP, or use any of its downstream USB 2.0 hub ports, you will also need to connect the upstream USB-A plug to your MBP. That should be fairly easy. I am guessing that you could use a USB-A port on a hub or dock, or any number of USB-C to USB-A adapters.

I don't think you'll find any MagSafe 1 to MagSafe 3 adapters. You'll need to charge your MBP from its charger or some power source other than the LED Cinema Display.

<< connecting the two devices has been disabled/locked out by changes to the OS/FW/HW. ??>>

Those displays have most certainly NOT been locked out.

If users would listen to the great advice that Servant of Cats gave to your original query, their A1306 display would be working with any version of MacOS that supports [mini] display port, or [Full Size] DisplayPort with adapter.

If they have the other one, they would still be waiting for their ThunderBolt-3 <-> ThunderBolt-2 adapter to arrive, so they won't quite know yet.