Što je bilo spojeno na USB port?
Maksimum mu je 500 mA
"USB port
If connecting a device without its own power supply directly to the USB port,
please note that the power consumption must not exceed 500 mA. If this value is
exceeded, you will have to use a separate power supply unit for your USB device
or connect a USB hub with a separate power supply. A USB hard drive and a USB
printer can be operated simultaneously on a USB hub."
Ako je bilo spojeno nešto što vuče više od 500mA možda je to razlog.