Hello! I've developed a board with an USB-Interface (USB-To-Parallel) using the FT245BL from FTDI. But my Windows-7-PC claims after connecting the board (for testing without the main-µC), that the hardware isn't properly working and it's listed as unkown device. I've attached the accordant circuit diagram. C4 and C5 are both 27p ceramic-capacitors. The power is taken by an external power-supply (USB Self-Powered Configuration). At my first attempt I used by mistake a 16 Mhz quartz anstead of 6 Mhz. Between AVCC and +5V I've later added a 500 Ohm-resistor. However, it isn't working - could have the missing resistor or the wrong quartz destroyed the FT245BL? My power-supply displays, that the FT245BL draws 20mA when it isn't connected to the pc and 0mA (yes, really zero) when it is (at the moment of connecting it increases for a very short time to about 60mA). I've no idea how to locate or to fix the problem, general how to approach. Thank you for help, Henning