MacBook Pro M4 with thunderbolt 5 and portable monitor

You have nothing that requires or can use Thunderbolt anything, and certainly not Thunderbolt-5. You paid dearly for that ThunderBolt-5 cable, and it seems to be a complete distraction in every way.

I recommend you try using a simple USB-C cable one meter or shorter, and see if that allows it to run the way you expect.

ToddGeorgeKelly wrote:

every single one of my cables works with thunderbolt four on the M4 Mac mini. But again, as has been said, not a single of my 27 cables works when using the thunderbolt five ports on the M4 Pro Mac mini.

The M4 Pro Mac mini is a different machine than the "MacBook Pro M4 with Thunderbolt 5" that the OP has. (Assuming that the OP is correct about having TB 5, that implies that the MBP has a M4 Pro or Max chip; one which had a plain M4 chip would only have TB 4.)

In the OP's case, it looks like the portable monitor works fine with the new MBP – as long as it is given its own separate power source, as the monitor manual recommends. The last set of power measurements show that monitor drawing an enormous amount of power (50W) from an external power bank, relative to specifications claiming that it uses 17W, and a manual saying that a 15W power source would be sufficient.

I don't know what monitor you are using, or what its manuals say, but I suspect that the M4 Pro Mac mini is not designed to offer huge amounts of power to external devices.

For that matter, I doubt if the plain M4 Mac mini is intended to supply 50W of power to external devices. Maybe the two have the same power supply, and you just got lucky with the plain M4 Mac mini because it did not need quite as much of the power from its own supply to run its own internal circuits.

I just had a web chat with apple and I asked the question, why does my portable monitor and cable work with M2 pro and not M4 pro, and this is what they said:

Apple

Okay, can you check if the cables that you are using support thunderbolt 5 connection?

Me

I very much doubt it. Both came with the monitor. Do I need specific thunderbolt 5 cables

Apple

Yes, can you try checking on the website for the manufacturer for the displays to check the type of connection the cables support.

Me

Could I just confirm something please. Are you saying that because I am trying to connect to the thunderbolt 5 port on the M4 Pro, I need to upgrade my cables

Can I rephrase

Does the thunderbolt  5 port require different cables to the M4 and M2 pro Mac minis

Apple

Yes, I am asking you to check the compatibility of the displays and the cables that you are using.

There are different type of thunderbolt connections used on old and new Mac mini computers

Me

So the new thunderbolt 5 port is not backwards compatible with my old cables

Apple

First you need to check if the displays that you are using support thunderbolt 5 cables

If they do, then you need to get thunderbolt 5 cable to connect the displays

The new type of cables with thunderbolt 5 will also support the old type of thunderbolt connections

I have 14" M4 MacBook Pro with the M4 Pro chip (14 core CPU/20 core GPU). As per attached screen shot the system info shows it as havingThunderbolt/USB 4. Why does it not say Thunderbolt/USB 5? I note that the speed is listed as up to 120 Gb/s.

Did you ever get to the bottom of this? I was about to buy a Thunderbolt monitor with the intention to use it with my new M4 Pro MacBook Pro. I like the idea of no power cables and plugging the monitor directly into the MacBook Pro with the appropriate Thunderbolt cable. But now I am hesitant.

I really hope you get some resolution to this important question. I’d appreciate if you keep us informed as I’m very actively looking for a thunderbolt monitor, but if I have to buy one that requires its own independent source of power beyond my M4 MacBook Pro, then that factor will certainly influence my decision.

Same problem with an MNN portable monitor.

I have an older MacBook Pro from 2019. I used the specific Apple branded Thunderbolt 5 cable I bought with my new MR Pro to connect to my portable monitor. Works fine. So the cable is fine and backward compatible.

Apparently, my monitor doesn't support Thunderbolt 5.

But here's the goofy part that makes no sense. I connected my M4 Pro to the same monitor using an HDMI cable. Nothing.

So, now I think it's the chip or some OS setting.

Maddening!

How is it possible that this isn't a a massive issue at Apple right now requiring an emergency upgrade?

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.