Another USB-C external monitor post--sorry!

[rogerdodger]

I have searched and can't find a definitive answer to this (maybe there isn't one?). I have a 2020 MacBook Pro with four Thunderbolt 3 ports. I bought an external monitor that has both HDMI and USB-C ports. If I use HDMI (with a USB-C to HDMI dongle and regular USB-C cable) it works fine, so the monitor IS working. Works with my kid's PS4 too over HDMI.
However, if I use the USB-C cable from one of the Mac's TB3 ports, to the USB-C port on the monitor, it gets no signal. I tried with the Mac running on battery power (as the USB-C should charge it) and also with the Mac's power supply connected. Same result, no signal.
Do I need a cable spec'd as Thunderbolt 3? I have read lots of stuff online suggesting the USB-C cable should work. But then I read other conflicting info as well, in fact it seems like it's a pretty fuzzy topic! Any advice greatly appreciated!

 

[OhMyMy]

Have you tried using a different USB-C cable? Not all USB-C cables are created equal.

 

[ascender]

Have you tried using a different USB-C cable? Not all USB-C cables are created equal.

This is probably the issue. Usually monitors will come with a usb-c/thunderbolt cable and insist you use that for a reliable connection.

Best bet might be to google for your monitor model and MacBook Pro to see what other people are using. Also check and see what the spec of that usb-c port is on the monitor?

The best cable I've used recently which solved some issues on my AV setup was the Belkin one Apple sell on their website. Why not buy one of those as you have the 14 day returns policy?

 

[arfung]

+1 on the USB-C Cable. If you're using a long cable or a thin USB-C cable, it's prob not gonna work - not carrying enough data for the video.

Try a cable that is <1 meter long and that is marked / advertised to be thunderbolt 3 or 4 compatible. I've had good luck with this one:

Anker USB-C to USB-C Thunderbolt 3.0 Cable (2.3 ft)

Rapid Charging: Supports high-speed charging up to 100W when used with a compatible charger. High-Speed Data Transfer: 40 Gbps transfer speeds mean you can tran

us.anker.com

USB-C / Thunderbolt cable standards are a mess. If you get a TB3/4 cable that is 1 meter or less, you should be in good shape. It should do both TB 3/4, DisplayPort, and high speed USB. But, some >1 meter USB-C TB3/4 cables do not transmit high speed (USB 3.0) signals or DisplayPort.

For instance, this 2m Belkin cable does high speed TB3/4, but is limited to only slower USB (2.0) speeds and would NOT work for some monitors (because no DisplayPort):

https://www.amazon.com/Belkin-Thunderbolt-Cable-Feet-Meters/dp/B072KPBKS3/