U2724DE, ASUS Zenbook S 13, TB4 no video

Dell never test ASUS. Did you check the ASUS Zenbook S 13 User's Guide for its TB4 specifications and usage?

In theory =

ASUS Zenbook S 13 First TB4 port --> ASUS AC power adapter
ASUS Zenbook S 13 Second TB4 port --> U2724DE TB4 cable --> U2724DE #7 TB4 upstream port (Online U2724DE User's Guide page 15)

@DELL-Chris M​ 

Hi, thanks for reaching out. I need to clarify that, I want to show my laptop video to the U2724DE monitor so I believe #7 is the correct port for me. <Correct! Fixed that. DELL-Chris M>

Since my laptop is using AMD CPU. I don't think it can formally support thunderbolt 4. I believe my laptop supports dp upstream(below manual, page 27,28 ). Here is my laptop manual:0409_E18916_UM5302TA_B.pdf (asus.com)

However, in Dell's manual of U2724DE, #7 port says it can alternatively support not only Thunderbolt 4 but also DP1.4, which theoretically support my laptop to upstream my laptop screen to the monitor.

In addition, my laptop perfectly works when I use U2722DE #5 port (page 14 in manual below) with the firmware version: M3T107

Here is the manual for U2722DE for your convenience:dl.dell.com/content/manual39176859-dell-u2722de-monitor-user-s-guide.pdf?language=en-us/

Agreed, the port does show as DP 1.4, but it is at root a TB4 port and TB4 cable, so that might be the issue. Unknown.

U2724DE #7 TB4 = TB4 4/DP 1.4 

U2722DE #5 port = USB-C/DP 1.4

@DELL-Chris M​ 

I can also exclude the problem of cables as well.

For now, I have 2 OEM cables from DELL:

1. typec-typec from U2722DE

2. typec-typec (with thunderbolt 4 sign printed on the cable) from U2724DE.

Both cables work when I connect my laptop to U2722DE (#5 port)

Both cables do not work when I connect my laptop to U2724DE (#7 port)

Now I think most likely there might be some incompatibility because of the monitor firmware. It looks like #7 ports failed to upstream videos from my laptop, which does not support TB4. 

I also took more tests. Here is the result on U2724DE:

1. 2019 MacBook support TB3, works perfectly with #7 port.

2. iPhone 15 Pro, supports USB-3, not thunderbolt 4, still perfectly works with #7 port. (I can see the video shown on the monitor, I can also use the keyboard that plug into the monitor.)

Since I just bought and received the U2724DE a few days ago. Do you recommend me return and wait for a monitor firmware update?

U2724DE #7 TB4 port and TB4 cable works on the 2019 MacBook and the iPhone 15 Pro. Fails on the ASUS Zenbook S 13. That means the fault lies with the ASUS Zenbook S 13, not the U2724DE. Dell is not going to create a firmware update just for ASUS laptops.

@DELL-Chris M​ I see. Thanks for your help anyway!