USB3.0 Loopback Plugs

[Smartmatic]

Hello ,

I am using the same PC , same USB3.0 port from PC and same test app(USB3.0Test) to perform test .
Some USB3.0 Loopbak Plug devices could be executed but some devices were not.
The devices which could not be executed would show USB3.0 Enumerated in the screen and test PC could not detect the device (as attached pics).
How can I fix the devices which could not be detected by PC?

Best Wishes
Joshua

[HamidK (PassMark)]

It is very likely that the USB3 lines that goes into the microcontroller are physically damaged. There are three possibilities:
- The USB connector is worn. In most cases it is repairable unless the PCB is damaged.
- The ESD protection circuits are dead. In most cases it is repairable.
- The main chip is dead. In this case, it isn't really cost effective to repair the plug.

There is a post here about common failure causes.
https://www.passmark.com/support/usb_device_failure.htm

[Smartmatic]

Hello ,

We have check our device for above three possibilities , the result are shown as below ~

- The USB connector is worn. In most cases it is repairable unless the PCB is damaged.
We observed the USB connector and did not found any USB worn.

- The ESD protection circuits are dead. In most cases it is repairable.
We do not have the schematic neither the information to compare.

- The main chip is dead. In this case, it isn't really cost effective to repair the plug.
We have check all of the device and they are working on USB2.0 test condition but not USB3.0 . In this situation we assume the main chip is fine.

We also read the Common failure modes in the link and do not think we have done the cases.
https://www.passmark.com/support/usb_device_failure.htm

We bought more than 30 devices a month ago and now there are six devices with the issue on USB3.0 condition , could you please offer some help to fix the devices ?

Best Wishes
Joshua

[HamidK (PassMark)]

In all USB cables and in our USB3 device, There are separate lines for USB2 and USB3, if the USB3 lines are damaged, then it could be why the unit is still working via USB2. If they are working at USB2 speeds that means the main chip is partially damaged. Unfortunately it is not cost effective to repair the main chip.
Given that you have six faulty plugs, it is highly likely you have (or had) a bad machine. e.g. it could be shorts in the wiring, ESD or missing ground connections.

You might want to review your testing activities and investigate possible faults with the devices under test, or your methodology.

You can also contact us via Email if you need some help.

[h3mp]

Both our USB3 loopbacks have done the same - now both only are usable on a USB2 port (on a usb3 port, the LCD claims they are enumerated, but the software doesn't see them).
We've just ordered a couple more, but i'm a bit worried on the reliability.
Can you provide detail of your ESD protection circuit so we can have a look into it here? - or should we just arrange to return them?
Thanks
Mark

[David (PassMark)]

This page details the known causes of this problem,
https://www.passmark.com/support/usb_device_failure.htm
(i.e. typically a ESD, or a bad host port).

ESD specs can be found at the bottom of this page
https://www.passmark.com/support/usb3loopback_faq.htm

But given the number of bad ports out there we have recently developed a new test device, the USB Short Circuit Tester.
This device is a lot more robust. It can take +-100V on the 5V line and a full short circuit on the port without being damaged.

So I would suggest using this short circuit tester before using any more expensive USB device.

You can also contact us via Email if you need some help.