USB cable not working w/1 screen, but fine w/other

[cmgolden]

Just getting my 10" touches up and working. One screen still has version 10 so I was going to update to match the newer version 11 screens.

But, screen 1 did not recognize my USB and cable.  I moved the cable to the other input jack, no joy.  I swapped cables, and a different cable worked.  (Bad USB cable, right?). I then tried the apparently bad cable in two other screens (running vers. 11) and it worked in both other screens.  Just not in the first screen.

Any ideas?

All of this was while running on backup batteries (~10.5 volts), but each screen was approximately the same low voltage.  Could that be it?  Why are the screens reacting differently to the same cable and USB drive?  USB drive was stock from a Dynon.

 

[Dynon]

If there's something marginal about the cable or stick, it could show up on one display and not the other just due to natural hardware tolerances. Or, if trying other cables or sticks produces the same results, it could be something up with the display. Are you basically using an off the shelf USB extension cable to get from the back of the display to the location of your choice? How long is the cable? How do the USB ports wired into the SkyView 37 pin harnesses behave?

 

[cmgolden]

The cable was an off-the-shelf, manufactured, panel-mount USB extension pluged into one of the 2 ports in the rear. 12 inches long.  A similar (but different manufacturer) 18" one worked fine in that screen.  The 12" one that didn't work (with the same stick) worked in two other screens.  I removed the USB cables wired into the D-subs, so can't confirm their operation anymore.
I guess I could just use the 18" one, since it worked, but that's about 8" longer than I need.

The same "defective" cable works fine plugged into my PC with the same stick.

Thanks.