usb stick not showing up on mac

I successfully moved files from a PC and old mac to my new(ish) mac, then deleted them off the USB stick. Now the USB stick is not showing up on the new mac and is showing as full on the old Mac. Can anyone help?

What is the format on the USB stick? What OS on the new(ish) mac? What IS the new(ish) mac? What do you mean "not showing up?" Have you tried Disk Utility to see it? Rebooting with it inserted? So many questions, so little information!

Read the link in my sig, post again.

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