ServoShield 16-Pin voltage issue?

Hello Everyone,

I am currently working to fix an issue with a servoshield connected to the top of an Arduino Uno. The issue is as followed:

There are 10 servo motors connected to a 16 pin servo shield which is getting power from a 5V DC power supply. Pins 1-10 work perfectly fine and the servos act as the should, constant rotation. Pins 11-16 is where things get messy, there is fluttering and shaking of the servo motors on all on the pins 11-16. Using a volt meter, the measured voltage coming through the red and black wires (Positive 5V and ground), the voltage is 5 volts. Now, When I measure the voltage through from the Positive 5V to the signal voltage (red and white wire), I am getting a jump up and down of 0.4 and 0.6 volts.

I am beginning to suspect there must be a drop in voltage somewhere along the signal pins in the 11-16 section, but I am not sure how to fix it. Could anyone be of help?