MacBook Pro M4 with thunderbolt 5 and portable monitor

HDMI cable does not carry power in either direction. Just signal.

if it's a high resolution display, the HDMI cable spec becomes important as well. Best results under 4K at 60 requires "PREMIUM" HDMI cables.

Longtimeusers1014--

the appropriate response in that case is to ask the display maker why a known-good sample of their product does not work with the latest MacBook Pro M4 PRO. The manufacturer has the Engineering expertise to find out why, and if it turns out to be a computer problem, to pressure Apple to fix it.

You will, of course, need to provide enough information about your setup so that they can duplicate and instrument that system in their lab.

Were you using BOTH displays as Hardware-accelerated displays? or was one or the other a DisplayLink or other type of "fake" display?

Did you install the same Driver software you had on the other machine or previous version of macOS?

Having the same issue. Just bought a UPERFECT 4K display. No signal on my MBP M4. Works just fine on any other computer.

Seeing conflicting reports here of whether a TB5 cable will fix the issue. Right now I can hook it up via 2 cables (HDMI and USB-C for power) and it works, but that's obviously not optimal.

I am also experiencing the same problem. I have a USB C portable monitor that I have been using with my 2020 M1 MacBook Air - it works flawlessly using a single thunderbolt cable. I just purchased a new M4 14" Macbook Pro, and it will not connect to the display using the same single USB C Thunderbolt cable that works with my M1 MacBook Air. I have the laptops side by side, and can swap the cable back and forth, works on M1, does not work on M4.

Is there any way to force the TB4/5 port down to TB3?

AndrewBergman wrote:

As indicated and cited above, both list support for DP over USB-C

USB-C (DIsplayPort Alt Mode) support refers to video signal – not to the provision of operating power.

So far, it sounds like the main issue is with these monitors wanting more power than a USB-C / USB4 / TB host port is required to provide. For whatever reason (intentional or not), the older MBPs provided "enough" extra power, and the newer ones are not doing so.

If there is a problem with the monitors not working with the DisplayPort Alt Mode signal from a Mac's TB5 port, when they have enough operating power (from other sources), that could be an issue, too, but it would be one which logically would involve a different part of the system than Power Delivery negotiation/provision.

The particular external display I've been testing with has 2 USB-C ports - I've tried with and without separate power and signal - with the same results. I've been using an Anker 4-port 100W GaN adapter to be able to power multiple devices simultaneously.

AndrewBergman wrote:

The particular external display I've been testing with has 2 USB-C ports - I've tried with and without separate power and signal - with the same results. I've been using an Anker 4-port 100W GaN adapter to be able to power multiple devices simultaneously.

It appears that the OP and you are dealing with different monitors and different root causes.

The OP's portable monitors displayed video when connected to a portable power bank and to a M4-series MBP at the same time. The OP posted a picture that appeared to show that in this configuration, the monitor was drawing 50 watts of power – far in excess of the amount that the monitor manual said that the monitor required. On top of that, the manual for the OP's monitors recommended the use of a separate power supply!

You are seeing no signal even when you are providing separate power to your monitors. That would seem to point to the video signal negotiation / connection rather than to the Power Delivery one.

AndrewBergman wrote:

The particular external display I've been testing with has 2 USB-C ports - I've tried with and without separate power and signal - with the same results. I've been using an Anker 4-port 100W GaN adapter to be able to power multiple devices simultaneously.

Does this monitor have any video input ports other than USB-C ports? I'm wondering if a possible workaround might be to use a HDMI-to-HDMI cable, or a USB-C to (whatever) adapter cable.

This is bad on Apples part to introduce such a bug. This one works well https://www.alibaba.com/product-detail/OEM-ODM-16-Inch-Portable-Stackable_1601143930193.html?spm=a2756.order-detail-ta-ta-b.0.0.298cf19cQLxrVK

Are you experiencing any issues when your MacBook goes to sleep mode? Every time my MacBook goes to sleep mode I need to unplug and plug again the USB HUB otherwise the monitors doesn't have signal

Outside of this specific scenario the HUB fixed the issue, good workaround. Thank you

"Are you experiencing any issues when your MacBook goes to sleep mode? Every time my MacBook goes to sleep mode I need to unplug and plug again the USB HUB otherwise the monitors doesn't have signal

Outside of this specific scenario the HUB fixed the issue, good workaround. Thank you."

In reply to GuilhermeSa

Good point. USB and Energy Saver have been at odds since USB was first invented. Energy Saver/Power/Sleep system settings have "put hard drive to sleep" option which can sometimes make the compatibility issues worse. Some hubs docking stations have their own manufacturer firmware update to keep up with USB standards. Ones that are powered by the computer typically are more sensitive than ones with their own AC/DC power adapter. This includes monitors and other devices powered by the computer.

Closing the laptop screen putting it in "Clamshell" mode automatically triggers sleep power levels on the USB of the computer. If people are having issues, look into your devices firmware, and see if you can get a comparable device with its own AC/DC power adapter to avoid issues. Power issues will persist once they begin, until the computer is restart.

I am a day trader. Upon one of my biggest trading days with the 13” M1 MacBook Pro. I decided to go to Best Buy and make an investment I bought a 14” M4Pro MacBook Pro (14 core CPU, 20 core GPU, 24GB RAM & 1TB SSD ) for my desktop since it has a fan I can do more one connected to the portable monitor in my room and I also got a 13” M3 MacBook Air ( 8 core CPU, 10 core GPU, 16GB RAM & 512GB SSD ) as my travel computer since normally when I travel I only use one 2 two websites some times that and 1 app. Tell my why my MacBook Pro just won’t power the monitor it registers for a little second then it disconnects after 9 seconds having the monitor plugged in through the type-c connector. More crazy after spending $2500 on a laptop my $1111 MacBook Air powers it just fine the only problem is that it thermal throttles and it starts to get really hot with the things I do in my office that why I thought the MacBook Pro would be a good fit in my office since I have a black theme going on in my office. But yeah brother I hear you I am really disappointed with the new MacBook Pro

<<. Tell my why my MacBook Pro just won’t power the monitor. It registers for a little second then it disconnects after 9 seconds having the monitor plugged in through the type-c connector. >>

Most users with this issue are using cables that are too long, or are not hi-spec (not necessarily hi-priced) cables.

USB-Cables for this use should have the USB SuperSpeed PLUS logo or the 10 G Bits/sec or 20 G bits/sec logon (or higher) on each end. Ordinary charging-only cables are not good enough.

In addition, the data rates are approaching the limits of switching times for this family of digital logic, and cables over ONE METER experience signal degradation, and the display kicks out.

The Inateck HB2030 hub arrived today, and I tested it by connecting it's USB-C lead to one of the Thunderbolt 5 ports on the back of the M4 Pro Mac Mini, and from the DP USB-C port on the hub to the Arzopa 2.5k 16" portable monitor, using the USB-C cable that was supplied by Arzopa. Sadly, the work around did not work as hoped! Power was delivered to the screen, but not simultaneously with video signal. Curiously, if I then connected the HDMI cable from the HDMI port on the hub to the mini-HDMI input on the portable monitor, then it did work. So the video signal and power coming from the TB5 port did managed to power and supply video, but only when the video was coming through the HDMI port on the hub!!

Your post mentioned the 10Gbps or greater USB-C video/data cable - I am not sure what the cable that was supplied from Arzopa is, but I imagine if it works with a TB3/4 port it should work with this hub also.

Hmm.