I/o device error on my 500Gb external hard disk(Freeagent)
how to solve I/O device error problem
More aboutdevice error 500gb external hard disk freeagent
You have two possible issues - the drive itself and the USB interface. If you can, try to remove the drive from it's enclosure and directly wire into a computer. If it still fails, it's the drive. If not, the problem has to be the USB interface.