I have 12 channel usb servo controller and it is powered via the 5 volt of a computer power(500 wats, BeQuiet). There is one micro servo motor attached to a channel. This motor needs max 200mA.
Now i can connect to the servo controller and the computer does see the card. When i attach the card to the usb port than the message of the baut rate. I say ok and the yellow led is flikkering once a second and the green led is even flikkering faster. The card is seen and the rerial number is seen. I can activate the channel where the motor is attached but nothing is happening. When i move the slider nothing happens. When i attach the 5 volt power cable to a disk controller in the computer it works, so i would think the power source works. The black is ground and the red is connected to the servo power + pin.
What could be wrong? I would think it should be possible to power the card from the 5 volt rail of a power source.