IMic Locks Up

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This is certainly a YMMV (your mileage may vary) article, but it seemed worth sharing. Server operators and mobile field users have run into situations from time to time when decoding just stops and can't be restarted, usually without rebooting the PC. Sometimes it's accompanied by the dreaded message, "An error occurred while attempting to open audio device. Audio format requested by the program not supported by the audio device." My experience is as follows: I noticed a server was no long sending data, so I remoted into it using VNC. I tried to stop monitoring and start again, but no change. Stopped and started the application, but selecting the USB Audio Device (iMic) yielded the dreaded "not supported" message upon starting monitoring.

Having no physical access to the server and fearing a reboot failure (all too familiar), I figured I'd try to uninstall the iMic using Device Manager. Fine, but when I did a "Scan for new hardware", it found the device but failed to fully install it, so it was not usable. Next, I thought I'd try disabling the USB Root Hub that contained it. I looked through the Root Hub properties' "Power" tab and found the one with a device drawing 100mA, which is what an iMic requests. I disabled the Root Hub, waited a few seconds then enabled it. This apparently must remove power to the USB device, therefore it reset it. The iMic then showed up properly in Device Manager and I was able to launch ATCS Monitor and monitor properly. Sounds like a lot of work and time, but it's not, compared to a reboot, and the risk of a reboot for a remote server may be something you don't want to fret over. My guess is that a powered hub may not reset so readily, but I'm not sure.

FYI, I had noticed that none of the USB Host Controllers showed resources used by the iMic, making the problem apparent...drawing power, but not using bandwidth.

-- GaryHahn - 03 Aug 2009