XMOS USB Audio not recognized by PC/Laptop

[ps3linux]

Dear Board,

I have this DAC “NF&J FX Audio – X7” it’s a good DAC and I have been using it with my tube amp for a while now, the USB interface is XMOS Audio, the micro-controller is (as much as I could read from the very dim etching) is XMOS 6l6C5 which turns out be a TQFP-48 package. The usb interface is “USB3343” by SMSC.
Recently the USB interface means XMOS part has stopped working, it is no more recognized by the PC/Laptop no matter whichever windows I try to use ( I have tried multiple PC/Laptops), however, the SPDIF, Coaxial part of the DAC works as always which leads me to understand that the USB interface has either died to something else with the interface. It is neither recognized as XMOS nor “unknown USB Device”.

There was no fluctuation in power, voltages across the pins of all ICs in the DAC are as per specification. Under oscilloscope the power supply is pretty smooth DC.

The manufacturer is based out of china so the communication issue is apparent and they are not willing to provide any service manual, etc.

With the experts here on this forum I need some general guideline as to the direction I should follow either I should try and replace the “USB3343” chip or is the micro-controller which requires reprogramming?

Since the mcu has a JTAG interface I am assuming that RT809H will be able to handle that part, if I have to reprogram the mcu where should I get the firmware.

[Ross]

You would have to get the xcore firmware from the vendor, it likely has custom modifications to interface with the custom external hardware of the product. Potentially the device could use a the secure boot functionality which would also mean its encrypted...

If it's just the SMSC phy you might get lucky with replacing it.

To see if its the xcore or phy I would check the SPI lines to see if the xcore if trying to boot. If it is I'd then check the reset line of the SMSC part, if the if xcore is trying to take out of reset then check it's providing a 60MHz clock out..

This is a forum for programming xmos devices, so this is off topic. Moving thread to "off topic".

[Aashvi78]

If your laptop or PC isn't recognizing your XMOS USB Audio device, make sure the drivers are updated and installed correctly. Try restarting your computer or connecting to a new USB port. If the issue persists, contact XMOS support for further assistance.PM kisan status