Very inconsistent Issues with Digital servo and arduino (am I wiring right?)

I am controlling one servo at the moment. The servo is very jittery and is acting inconsistently. Can anyone help me?
Thanks in advance

0090-10 Control Box Schematic.pdf (569 KB)

What are the things with the five connectors? One is going to the RESET pin on the Arduino so that could cause the Arduino to reset. Why do they have two Ground connections? Maybe you have made a programming mistake. What is your sketch?

Sorry but a picture containing a load of unidentified components is not helpful. Particularly when most of them have two ground connections for no known reason.

The most common problem with servos jittering is insufficient power. So exactly what servos are they, are they specified for 7.2V and how much current can your DC-DC converter supply?

Steve