I purchased the DFR0524 display a week ago. I have scrupulously followed the instructions given here: https://wiki.dfrobot.com/5.5__HDMI_OLED ... KU_DFR0524
However, the raspeberry PI 3 B + does not recognize the touch when it is connected to the USB (verified with the lsusb command).
I tried to connect other peripherals that are correctly recognized.
I use a 2.1A power supply to power the raspberry.
The USB cable with which I connected the touch screen works.

Can the display be defective or is there anything I can try to fix it?

Thank you
Hi, thank you for your support and contact.
If there is no response when plug the display to the raspberry Pi 3B+, please check whether the raspberry Pi recognize USB device plug-in, or you can try plug it to the computer to check whether it can be recognized.