Technical Support

MCB2140: USB LED OR USBCV TEST FAILS

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Information in this article applies to:

• MCB2140 Evaluation Boards

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QUESTION

On the MCB2140 board the USB examples run fine, but the USB LED does not work and the examples do not pass the USBCV tests.

What could be wrong?

ANSWER

On some MCB2140 boards produced in November 2005, the resistor values R39 and R38 were reversed. Make sure that the value of R39 is 10K and R38 is 100K as stated in the MCB2140 schematics.

Make sure that you are using the current versions of the USB example projects available under:

• LPC2148 USB Mass Storage Device Example
• LPC2148 USB HID (Human Interface Device) Example
• LPC2148 USB Audio Device Example

MORE INFORMATION

• Refer to USB Interface in the MCB2140 User's Guide.

Last Reviewed: Monday, September 11, 2006

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