Is is possible that a standard servo could interfere with anther device? Im currently using a MP3 Trigger attached to the Arduino and whenever the servo activates the status light on the MP3 trigger board flashes and resets. Both are connected to the arduino 5v and GND through a breadboard.
Hi, The servo might be drawing more current than the Arduino can supply, this can be on power or the signal. In my case I had this problem on the signal wire, try connecting to the servo signal wire through a current limiting resistor, I don't recall the value I used, but try something around 200 or 300 ohms to keep the current around 20-25 Ohms.
If the servo is under load, it may be that it requires more power in which case you will need a separate power supply for it, but try the resistor on the signal line first, it solved a very similar problem to yours for me.