will my usa bought passport drive work if attached to a new german bought pc running on 220volts or will it fry it ?
You are connecting the drive to the USB not the power connector so there will be no problems
USB will only provide enough power to make the drive work
The Passport derives its power from the computer’s power supply through the data cable. If your computer has a voltage selection switch, please set it to the locally distributed voltage level, (220 or 240 VAC). This power supply is a “switching” power supply and will furnish the same output voltage and amps to the hard disk drive regardless of what its input voltage is.
As long as your computer’s power supply is set correctly for the locally available voltage, the hard drive will operate without a problem.