Externally Powered Servo Crashing Arduino

I have a project that utilizes a common hobby grade servo; to avoid potential power problems, I am powering the servo externally (i.e. not from the Arduino). Power is provided to the servo via a 4 x AA battery pack (6v, within the limits of the servo), with a common ground connecting the servo to the Arduino.

The Arduino crashes constantly usually about 100 milliseconds into the program. If I disconnect the power to the servo WITH NO OTHER CHANGES (meaning the servo code is still running but no power is provided to the servo), the program runs flawlessly with no crashes. These seems like it must be a power issue, but the setup is so simple I don’t know what I could be doing wrong.

I do note that my program makes use of interrupts (not the same timer used by Servo library), but I don’t think this is the issue based on the behavior described above.

I used Fritzing to create breadboard and schematic/cicruit views (attached).

Any suggestions??

If the wiring is perfect, that leaves the code.

CPARKTX: I do note that my program makes use of interrupts (not the same timer used by Servo library), but I don't think this is the issue based on the behavior described above

It would only take a few minutes to write a short sketch using the servo library to see what happens with it.

Do you have another servo that you can try in case there is a fault with the first one?

What is the other thing connected to the Arduino?

...R

The servo "sweep" example code could be used to do a simple test of the hardware setup.