It is normal for the motors to beep a few times during startup; usually playing a melody. If they continuously beep at regular intervals then it means the ESCs are not getting any RC signal. Check and re-check your wiring!

Ensure proper board operation by using a battery at the same time as USB and use the MultiWii Config GUI to ensure the board is communicating OK. If the Quadrino is communicating with the GUI then it is definitely a wiring issue as the Quadrino sends the RC signal from the moment it powers up.

Check the following:

1. Are all motors beeping, or only 1 or 2? It can be hard to tell when they beep in sync.
2. EZ-connect is fully inserted into the board. Remove the cable and re-insert it.
3. 3-pin connectors between the EZ connect cable and ESC are fully inserted.
4. Check that there is a path for ground (GND) between the Quadrino and each ESC.