Transcend usb 3 card reader!

I have a new, just out of the box, 27inch iMac.

When I connect my usb card reader it does not light up or show anywhere on the Mac when plugged into any of the Mac's USB ports.

I have however kept my old Mac's usb wired keyboard, when I connect that to my Mac and then connect the card reader to one of the built in USB ports on the wired keyboard, the card reader lights up and displays on the screen.

This proves to me that the card reader functions.

I know the USB ports work on my new Mac as I have other products plugged into them.

I could of course keep plugging my old wired key board into my new Mac when I use the card reader but that seems self defeating!

Any suggestions gratefully received.