MacBook Pro M4 with thunderbolt 5 and portable monitor

I'm not a Mac owner, but I also suffer the same issue on my Windows machine (Lenovo Yoga Slim 7x - Snapdragon X Elite ARM64).

I found this thread on Google, while researching for this issue.

I believe there's a problem with how these displays communicates with the host device. It's probably not following proper handshaking rules. My display's an Arzopa Z1FC.

It seems to affect USB4-Capable devices. Other devices that aren't officially USB4 capable seems to work.

One example I know is that it works fine with the ROG Ally (which isn't USB4 capable), but doesn't work with the ROG Ally X (which is USB4 capable).

The most notable thing is that when you connect the Arzopa display to the computer, it'll just detect it as an USB 3.1 Hub, and nothing more.

However, if you power the display first (either by using an USB-A to USB-C cable connected to your computer, or using an USB-C charger) and then connect the USB-C cable, the display will properly work.

If you mix that order (plug the display first and then supply power to the display), it'll just slowly (25W max) charge your device.

Unfortunately, you'll always need to use two cables to this portable monitor - one for power, other for video output - if this display doesn't properly communicate with your computer.

The only way I found to have "a single cable" was to buy a cheap USB-C hub with HDMI out and USB-A out, and use that USB-A to power the display and the HDMI out to send signal to the display. It kinda screws the portability, but it's a way to have it on a single cable again.

Hope that helps for the time being. Unfortunately, I think that's a matter of these brands figuring their stuff out and possibly sending a firmware update... Idk.

btbwoo87 wrote:

bump

one reader posted here that all that was required for their display to work was the vendor to "Get with the Program" and make a small firmware change.

Solutions already posted include:

• Buy the model that works from the vendor cited

• pressuring the Vendor to make similar firmware changes

• Provide additional power with an external power adapter or an additional cable for power.

I just came on to see if there were any updates on this? It's been a few months, surely there has to be a software fix for this. I already paid for a monitor and $2400 on an M4 Macbook Pro, I don't want to buy more stuff!

Sean1397,

Your guess is as good as our's. The first step is to contact AppleCare by phone or reach a genius bar or Authorized Apple Service Center and get a case #.

This is just a user to user forum with Apple moderation.

The number of times in 24 years I've seen Apple moderators actually say they are looking into a problem can fit on one hand.

This issue has been as much an issue with some older Apple displays as third party displays.

There are three places this can break:

1. The thunderbolt bus on the Mac and the kernel extensions addressing them, and any firmware speaking to it, and any differences in the kernel extensions of one operating system versus another. To isolate the operating system issue, downgrading is possible through steps listed on this tip. Energy Saver settings put hard drive to sleep can impact the USB and Thunderbolt bus on Macs, espceially when closing a laptop lid as the bus goes into low power mode. Once in low power mode only a fully powered laptop on restart with the display lid open will give you full power. This is even greater problem with displays powered by the Mac itself with no power of their own.

2.The use of less than optimal cables. Make sure you are using cables that least have the lightning bolt icon on the sheeth. Those without may be straight USB-C cables and those don't have as good a video signal carrier.

3.The thunderbolt bus on the display, and any firmware provided by the display manufacturer. Additionally displays with their own separate power source from the computer are less likely to be flakey with Energy Saver. Consult with the display manufacturer support if any firmware update is planned for supporting Thunderbolt 5.

This can't be exclusive to the TB5 controller as the new M4 Macs have 1 TB4 port too. this should be something apple can address in software. It appears this display is getting power but the display signal is not getting triggered.

dragos-florin wrote:

Here's with a 145w power bank connected, both laptops testes in the same setup and work as expected , monitor using ~50W.

https://discussions.apple.com/content/attachment/53810b76-01b0-4316-a672-5326d730c8ee

Now, I stick with my original question, why the older tb4 can negotiate the power but not the new one? I tested also with a smaller OLED monitor, same issue.

If the monitor worked with the older MBP, using the amount of power that you showed us in your previous photo, you got lucky. That amount of power was well below what the manual monitor said that the monitor wants, even though both MBPs were within their rights to offer that amount of power – or less.

The USB 3.0 standards only call for host ports to offer 900mA of 5V power (i.e., 4.5W), so if the MBP was giving the monitor 12W, whether through PD or through the monitor just taking it anyway, that was well in excess of the amount that the MBP needed to provide as per USB 3.0 specifications.

As for Power Delivery power, I could be mistaken, but I do not believe that either MBP was required to offer any of that at all. Apple advertises that the MBPs can charge over USB-C, not that they charge other devices over it.

Now you are showing us a photo where your portable monitor is drawing 2.49A at 20V – for a power draw of 50W. This from a monitor whose specifications say it uses 17W, and whose manual implies that a 15W supply would be sufficient and a 30W supply would be recommended.

VikingOSX wrote:

All of the M4 MBP 16-in configurations on Apple's Online Store show three TB5 ports in the configuration. All of the M4 MBP 14-in configurations show three TB4 ports.

All MacBook Pros with plain M4 chips have three Thunderbolt 4 ports. These are entry-level MacBook Pros and Apple only offers them in the 14" screen size.

All MacBook Pros with M4 Pro and M4 Max chips have three Thunderbolt 5 ports, whether the chassis has a 14" screen or a 16" one. These ports support both Thunderbolt 5 and Thunderbolt 4.

I've added a new thread here for the purpose of finding a portable monitor that is compatible with Thunderbolt 5 macs. Though I also see oliverfromoslo's point, that suggesting suitable monitors in this thread would also help solve the problem.

Servant of Cats,

You ask..."Please provide a link to the Technical Specifications which state that

the M4 Max MacBook Pro will provide large amounts of power – in excess

of the minimums for USB or Thunderbolt ports – to an accessory. I am

looking at the stated specifications, and I see nothing to that effect

there."

I as an impartial observer can understand the consternation some might have about this.

Their older, less expensive equipment is supporting the hardware that their newer hardware is not.

Apple has a history of declaring equipment vintage:

Obtaining service for your Apple product after an expired warranty - Apple Support

And then not offering system upgrades for those equipment eventually making it difficult to find more current software for their Macs.

To buy all these peripherals only to find new equipment no longer supports it is a very hard blow.

It is my firm belief for people who suddenly get surprised because some older hardware is no longer supported, to go both to the manufacturer of that older hardware and ask AppleCare to look into the issue to see if one or the other can offer some firmware update to fix these issues. I wrote this tip to show that this isn't isolated to Apple, but an ongoing issue with standards of USB-C and Thunderbolt across the industry.

USB/Thunderbolt & Energy Saver/Sleep/powe… - Apple Community

Just because the specs do not say something is directly not supported, past history of supports lends to the misimpression they should have continuous support. Calling it a newer Thunderbolt or USB-C lends to the impression it should be able to support what the older Thunderbolt or USB-C did. This is where communication is key. That customers reach out to both Apple Support (AppleCare) and the manufacturers of the devices to find out where the actual support broke down with newer equipment.

up_mambo wrote:

So, what can we infer from these data points?

The Macbook Air has 2 USB4 ports that support : (Charging, DisplayPort, and Thunderbolt3)

•

The M4 Macbook Pro has 3 Thunderbolt 5 (USB-c) ports that support (Charging, DisplayPort and Thunderbolt5)

In those specifications, "charging" means charging the Mac.

Charge your MacBook Air or MacBook Pro - Apple Support

"Your Mac has USB-C ports, and may also have a MagSafe 3 port. If your Mac has both ports, either can be used to charge your battery."

yoavarden,

If you want a fix, start a new topic thread. There are 130 posts in here. If the posts in here do not answer your question, you are better off asking the community as a new thread. It is extremely hard to know who is responding to what in a long thread.

You want to know which make and model monitor works with Thunderbolt 5 on your make and model year of Mac with what model thunderbolt cable. When you get that answer great. Recycle the equipment that doesn't work, and get equipment that does. The manufacturer of your monitor does not know how to keep up with standards if they won't respond to making a new firmware update for your thunderbolt.

OK.

That picture shows that the monitor is getting power when attached to the new MBP. It just isn't getting signal. I was under the mistaken impression that the monitor was showing nothing at all, as if it did not have its own power source, and was not getting power from the MBP, either.

That first link leads to a page for several monitors. Yours is appears to be the J5.

The J5 is a 17.3" monitor with 3840x2160 pixel resolution and a 60 Hz refresh rate. It has two USB-C inputs and a HDMI input, plus a downstream Micro USB-B port. The specifications say that it does not have a built-in battery – and that its rated power is 17 watts. The monitor has an IPS panel and 100% coverage of Adobe RGB – both good specifications that don't matter for the purpose of troubleshooting here.

3840x2160 @ 60 Hz is bog-standard and well within the capabilities of your MacBook Pro, whether you use one of the MBP's USB-C ports, or use the MBP's HDMI port.

Here's the manual .

In Chapter 3 of the manual, under Type-C signal transfer, and again under HDMI signal transfer, they say

"Note: 4K monitor needs higher voltage power, for a more stable power supply, it is recommended to use our original PD adapter to power."

In Chapter 6 of the manual, under Q&A, they say

"Q: The monitor keeps switching and flicker, although it connected to outlet for extra power supply.

A: This situation is generally caused by insufficient voltage. Please check whether the factory-packed cables are used, and then check whether an external PD power supply is used. The power consumption of 4K monitor is relatively larger, and an external PD power supply is required."

They also say that the monitor requires at least a 15W power supply, but that their power adapter provides 30W, so that if you use a power bank (external rechargeable battery), one "with output above 30W is recommended."

Part of USB-C Power Delivery is that the power supplier negotiates with the power consumer as to what voltage to offer. The original standard allowed power transfers of up to 5A at up to 20V (up to 100W); the current one allows power transfers of up to 5A at up to 48V (up to 240W).

If I look at the fine print on the bottom of a 29W Apple USB Type-C power adapter, I find the words "Output: 14.5V === 2.0A (USB PD) or 5.2V === 2.4A." Both my MacBook and my iPhone charge off this adapter, but if either was picky enough that they would not accept anything less than 20V, they would be in trouble.

So the highlighted parts of the monitor manual raise some follow-on questions:

• What "higher voltage" does the monitor expect?
• What voltage is the old MBP offering?
• What voltage is the new MBP offering?
• Could the voltage that the new MBP is offering be high enough to let the screen come on and display that "No signal" message, but not high enough to let the electronics to receive a signal work properly?

The original post described a certain hub that solved this problem, in that it at least enabled, without a separate power connection, a direct link between the Thunderbolt 5 port and the USB-C port on the portable monitor. It is very expensive in the UK (currently at time of writing £96 on Amazon).

Does anyone know if this Startech hub works with the same effect? It has USB-C DP Alt Mode which apparently very few hubs have, so I think it might work. However, on Startech's website for the hub, it states the following:

• USB-C VIDEO OUTPUT: USB-C port (video + data) supports video out to a 4K 60Hz portable or desktop USB-C monitor; NOTES: Computer must support USB-C DP Alt Mode; Power adapter must be connected to PD Pass-Through port to power a USB-C monitor

This makes me think it possibly won't work in the same way that the recommended Selore hub would. Which would be a pity as it's currently £36 cheaper!

Remain calm. Don't get distracted by ThunderBolt-5, it simply is not a factor here.

ThunderBolt-5 cables and ports run differently ONLY when each and every device involved is genuine ThunderBolt-5. Otherwise, they are indistinguishable from ThunderBolt 4 and ThunderBolt-3, which are electrically identical and barely different from each other, except by some arcane support for multiple devices on one cable.

When All devices are Thunderbolt-5, the regular baseband data stream (one bit per signaling interval) changes to a modulated signal (3-patterns per signaling interval) for increased speed. Nothing else of substance changes.

when all devices are NOT Thunderbolt-5, it all works as if it were Thunderbolt-3. If connecting only USB devices, it all works as USB devices.

-------

Readers here report that main issue for Bus Powered Displays is that they don't get enough Bus-power using one port.

You can check whether the device is getting all the power it needs by invoking:

 menu > about this Mac > (system report) ...

... and checking this display:

...