U3219Q, MacBook not detecting video signal

I found the data = U3219Q

Built = October 20, 2020, 4 years/244 days old
Shipped = January 21, 2021
Warranty expired = 1 year/4 months/30 days ago on January 22, 2024

What specific MacBook model?

Using the provided U3219Q DP to DP cable and USB-C to USB-C cable, and retail HDMI to HDMI cable, can you test the U3219Q on a Windows OS computer to see if it works on any video IN port?

My Macbook is an M2 MAX, running on Ventura 13.7.6.

But here's the strange part : the monitor is not taking clean signal from ANY device using HDMI or USB-C.
I tried my Canon camera : same issue.
I tried a Nintendo Switch : same issue. 

What's odd with the Macbook is that the screen does extend (in my Mac setting, it appears and I can move its position, and my mouse pointer can get out of the macbook screen and venture - invisibly - where the Dell monitor is... but the DELL Monitor keeps showing "No Signal"...

I don't have access to a Windows/PC at the moment unfortunately...

Try this "no cables/power button reset" again. If you still have the issue, then the U3219Q has a faulty internal component. 

* Turn the U3219Q off
* Disconnect the power cable from the U3219Q
* Disconnect every other cable from the U3219Q
* Disconnect any USB-A device from the U3219Q
* Disconnect the Ethernet cable from the U3219Q
* Press and hold the U3219Q power button for 8 seconds

* Disconnect the USB-C cable from the MacBook
* Restart the MacBook with lid open

* Connect the power cable to the U3219Q
* Connect the USB-C cable to the U3219Q
* Turn the U3219Q on

* Connect the USB-C cable to the MacBook

No, this doesn't work.  I've tried several times.  

My opinion, time to replace it.