hey i need help... im doin a finger print project.. ive connected the serial interface and the finger print device, bothe soldered on a pcb and grounded separately.... an external power supply is connected to the PCB.. when i switch it on.. the finger print device glows blue for a second and then disappears and also the small red blinker in the serial interface device... but the external power supply device still glows red... what im tryin to ask is... is the finger print device still working..cos evrytime i switch it on..the blue light appears..i tried connecting the serial port from the laptop without the external power supply..yet the blue light blinks for a second.. and also the external power supply device blinker glows red... can anybody help me understand what seems to be the prob..??