One of my picore devices is placed on my workbench. I always power it down when I'm not using it.

I noticed that on several occasions, the USB Wifi stick itself is not detected at boot. This happens apparently at random. I can boot ten times without problems and then several times with the stick not being detected. When that happens the blue LED of the stick doesn't glow.

I already tried another USB-stick and changed the "waitusb" on the bootcodes page from 2 to 5 but it doesn't make any difference.

Here are two pictures to show what happens at boot:

USB stick detected
Name:  detected.jpg
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USB stick not detected
Name:  not-detected.jpg
Views: 234
Size:  114.4 KB

Anybody any idea as to why this happens?