[Elecraft] Asus Xonar U7 failure

[ab2tc]

Hi,

When I came down in the shack Sunday morning, my shack PC was unexpectedly
turned off. When I switched it back on, the U7 refused to enumerate with the
following detailed message:

http://ab2tc.com/u7_failure1.png

Several more disconnection and reboot attempts produced the same failure.
Taking the U7 to my laptop again produced the same failure. The cable was
not the same on the laptop so cable failure can be ruled out. I actually
tried a third cable on the laptop to no avail. One symptom I noticed is that
the blue LED on top only blinked a few time then remained off. On a normally
working unit the LED comes on quickly and stays on. From my experience with
USB at work, this type of failure means the PC sees the pullup resistor, but
is unable to retrieve the device descriptors from the device. This rules out
anything to do with configuration of the device or the PC driver. Has
anybody else had a USB failure with the U7/U5 models?

Well, accepting defeat I got out my brand new U5 which was intended for
portable summer use with my older K3 and hooked it up to the K3S. It works
fine but isn't as quiet for noise and spurs as the U7. See here for links to
screen shots of both:

http://ab2tc.com

Is there any reason the two models should be different or is this just a
random device difference? I need to know as it makes my decision whether to
buy a replacement U5 or U7. I prefer the U5 since all the connectors are on
the back which is much more convenient, but if there is any doubt that the
U5 has equivalent performance, I will stick with the U7.

AB2TC - Knut



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