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USBtest 2000

Technical Support Questions & Answers

  1. What is the USBtest 2000?
  2. What is TESTHUB?
  3. How do I hook up the USBtest 2000?
  4. How can I get more detailed information about my error?
  5. I want to test hubs with the USBtest 2000, how can I tell if my USB port is good?
  6. Can I run the test under Windows?
  7. I can run TESTHUB or TESTUSB a few times but then it fails enumeration. Why?
  8. Why would the software tell me that it could not find a host controller?
  9. Why would the register test fail?
  10. Why would the port test (TESTUSB) fail the connect test?
  11. Why would the hub test (TESTHUB) fail the connect test?
  12. Why would the port test (TESTUSB) fail enumeration?
  13. Why would the hub test (TESTHUB) fail enumeration?
  14. Why would the high speed pulldown test fail?
  15. Why would the loopback test fail?
  16. Why would the USB Vcc voltage test fail?
  17. Why would the USB Vcc loaded voltage test fail?
  18. Why would the USB shield continuity test fail?
  19. Why would the port test (TESTUSB) fail the USB SOF frequency test?
  20. Why would the hub test (TESTHUB) fail the USB SOF frequency test?
  21. Why would the USB low speed test fail?
  22. Why would the USB low speed loopback test fail?

  1. What is the USBtest 2000?
  2. It is a USB peripheral that can measure parameters relating to proper electrical operation of the bus. Software supplied with the USBtest 2000 that runs on the host computer instructs it to run tests that are appropriate for testing USB ports on a computer or for testing USB hubs.

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  3. What is TESTHUB?
  4. TESTHUB is the host software for testing a USB hub with the Sycard USBtest 2000 (the full file name is TESTHUB.EXE).

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  5. How do I hook up the USBtest 2000?
  6. The USBtest 2000 needs a wall adapter for power (see the instruction manual for information on this). For host controller port testing, connect the USBtest ports (labeled "Port 0" and "Port 1") to the host controller's USB ports. Since the tester ports are independent, they can be connected in either order. If only one host controller port is being tested, it can connect to either of the USBtest 2000 ports. For hub testing, connect the hub to the USB host controller, and connect the USBtest 2000 to the desired hub ports. Note that while not all hub ports need to be connected to the USBtest 2000, if you are not testing hub ports 1, 2, 3 and 4 you will have to use the -p and/or -z command line options. Also note that only the ports connected to a USBtest 2000 can be tested.

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  7. How can I get more detailed information about an error?
  8. Use the -v2 command line option?

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  9. I want to test hubs with the USBtest 2000, how can I tell if my USB port is good?
  10. Use the TESTUSB software to test just the port hooked to the USBtest 2000.

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  11. Can I run the test under Windows?
  12. No. It has to be run under real mode DOS. You run real mode DOS by typing the key just after the computer beeps during boot, or enter windows and then from the "Shut down" menu select "Restart the computer in MS-DOS mode?"

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  13. I can run TESTHUB or TESTUSB a few times but then it fails enumeration. Why?
  14. This problem can be caused by having USB interrupts enabled in the BIOS. Run SETUP for the BIOS and disable USB interrupts.

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  15. Why would the software tell me that it could not find a host controller?
  16. If there is no USB host controller in the machine. If the host controller has a problem with its connections to the PCI bus or an internal problem. Some PC chipsets can enable and disable the host controller, and if it is disabled it will not appear on the PCI bus as a device. The BIOS settings for your machine may affect whether the USB host controller is enabled onto the PCI bus. If the optional -s or -b command line parameters are wrong.

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  17. Why would the register test fail?
  18. This could happen due to a bad host controller or a problem with the PCI bus. It could also occur if the BIOS setup menu is configured correctly (see "Why would the port test fail enumeration?", below).

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  19. Why would the port test (TESTUSB) fail the connect test?
  20. If there is no device connected to the port of the host controller that is being used, this test will fail. Check that the USBtest 2000 has power. Also, if the device connected to the host controller port is a low speed device this test will fail. This may be caused by testing a USB port that is not connected to a USBtest 2000. Check the connections and reset the PC and the USBtest 2000 and try the test again.

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  21. Why would the hub test (TESTHUB) fail the connect test?
  22. If there is no device connected to the port of the host controller that is being used, this test will fail. For self-powered hub testing, check that the hub has power. If testing bus powered hubs, make sure that the hub is properly configured for bus power. Also, if the device connected to the host controller port is a low speed device this test will fail. This may be caused by testing a USB port that is not connected to a hub. Check the connections and reset the PC and the USBtest 2000 and cycle power to the hub and try the test again.

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  23. Why would the port test (TESTUSB) fail enumeration?
  24. Check the BIOS setup menu (most machines tell you what key [e.g. F1 or DEL] to hit to get to the setup menu when the machine is first powered on). Look in the setup menu for USB related items and try disabling USB keyboard, USB interrupts and other USB BIOS features.

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  25. Why would the hub test (TESTHUB) fail enumeration?
  26. Check the BIOS setup menu (most machines tell you what key [e.g. F1 or DEL] to hit to get to the setup menu when the machine is first powered on). Look in the setup menu for USB related items and try disabling USB keyboard, USB interrupts and other USB BIOS features. Check the connections and power to the USBtest 2000.

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  27. Why would the high speed pulldown test fail?
  28. If the 15k ohm resistors specified in the USB specification revision 1.1 section 7.1.5 are considerably out of range this test will fail. Check the pulldown resistor on the D- line.

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  29. Why would the loopback test fail?
  30. The loopback test sends blocks of data to the USBtest 2000, and the USBtest 2000 sends these back to the host. Check for marginal connections or drive levels. Check that any series resistors on the USB data lines (D+ and D-) are correct. Check that any EMI reducing components (ferrite beads or capacitors to ground on the USB data lines) are correct and are not interfering with the signal quality.>

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  31. Why would the USB Vcc voltage test fail?
  32. Check the overcurrent protection device to see if it is open or has high resistance. Check the system or hub +5V power supply.

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  33. Why would the USB Vcc loaded voltage test fail?
  34. The overcurrent protection device resistance is too high, the USB cable used to connect to the USBtest 2000 has too high a resistance, or the system or hub +5V power supply is weak and getting loaded down.

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  35. Why would the USB shield continuity test fail?
  36. Check that the shield connection has good continuity to the host or hub ground. If the USB connectors are not mounted on the same board as the host controller or hub chip, check that the board or bracket that the USB connectors are mounted on is properly grounded to the system or hub ground.

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  37. Why would the port test (TESTUSB) fail the USB SOF frequency test?
  38. Check the host controller frequency source. The problem may be that a clock synthesizer was used that is not accurate enough to meet the USB Revision 1.1 specification section 7.1.2 requirement of 500 PPM accuracy. Check that the crystal driving the host controller clock source is the correct frequency and that the load capacitors for this crystal are correct.

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  39. Why would the hub test (TESTHUB) fail the USB SOF frequency test?
  40. If the "bad frame rate" error is reported, than check the host controller frequency source. Otherwise, check the hub frequency source, particularly the crystal or resonator and its load capacitors. This test also runs some general USB traffic, so check for marginal connections or drive levels. Check that any series resistor on the USB data lines (D+ and D-) are correct. Check that any EMI reducing components (ferrite beads or capacitors to ground on the USB data lines) are correct and are not interfering with the signal quality.

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  41. Why would the USB low speed test fail?
  42. If the 15k ohm resistors specified in the USB specification revision 1.1 section 7.1.5 are considerably out of range this test will fail. Check the pulldown resistor on the D+ line.

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  43. Why would the USB low speed loopback test fail?
  44. The loopback test sends blocks of data to the USBtest 2000, and the USBtest 2000 sends these back to the host. Check for marginal connections or drive levels. Check that any series resistors on the USB data lines (D+ and D-) are correct. Check that any EMI reducing components (ferrite beads or capacitors to ground on the USB data lines) are correct and are not interfering with the signal quality.

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