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| How to debug a USB 3 connection? |
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| wraper:
How could I miss this :palm:. H1-H4 pads of edge connector are not grounded. Not only it's mechanically weak (I would even avoid using thermal relief on those), basically cable shield is left not connected :horse:. Now it's obvious why it fails to work as USB 3. Yeah, 3 different errors on such simple board :palm:. |
| Jackster:
--- Quote from: wraper on December 02, 2018, 01:50:17 am ---How could I miss this :palm:. H1-H4 pads of edge connector are not grounded. Not only it's mechanically weak (I would even avoid using thermal relief on those), basically cable shield is left not connected :horse:. Now it's obvious why it fails to work as USB 3. Yeah, 3 different errors on such simple board :palm:. --- End quote --- I forgot to mention that we noticed that and put a mod wire in to fix the prototype. |
| wraper:
I guess this has something to do with not connecting diff pairs in certain cable orientation or running diff pairs in parallel. I won't dig into type-C spec now as it's late night here but cables most likely have only one set of differential pairs (3 diff pairs in total, not 6). So running 6 diff pairs like this might cause connection working on only certain matching orientation of cables (1/4 chance of success considering missing D lines on one side) or even cause diff pairs connected in parallel through the cable. |
| wraper:
Full featured type C cable seem to have 5 diff pairs. Only one diff pair for USB 2. So as I understand schematic should be like this: |
| wraper:
Oh, and Vbus trace is way too thin for supplying any serious current as it should according to USB spec. It should be much thicker and have separate traces running from all 4 pins joining into one thick trace. Not running through other 2 Vbus pins of female connector. Via stitching of GND is inferior for such high speed application as well. |
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