I had problems on 5 computers not seeing my teensy, The two USB cables worked with everything else but not my teensys.
Then I tried a small usb cable and my teensy worked right away. The shorter the cable the better, hope this helps.
What was everything else? Shorter USB cables should not make a difference. Make sure the longer cables are not charge only cables. They do not have the data lines connected...
I can't believe I din't check that, all the other devices the cables are used on are for charging only. How stubborn was I, even my wife suggested that they may be charging cables only . Thanks for the correction wwatson, you are right, to me a usb cable was always for usb data not just power only. Live and learn!.Thanks.
That has bit me more than once Would be nice if there was some kind of standardized color coding for charge only USB cables.
Glad that took care of it...