Computer screen flickers while servo motors are moving

Using Arduino Project Guidance
1

My computer screen flickers while servo motors are moving, the servo motors are powered by an external power supply the grounds are connected.

I am thinking that there is some type of feedback from the arduino going through the USB.

2

My computer screen flickers while servo motors are moving

What kind of servo motors?

I am thinking that there is some type of feedback from the arduino going through the USB.

Maybe. Why is the Arduino connected to the PC?

3

I got connected 6 Hitec servos 2x HS-805BB, and 4x HS-322HD. The Arduino is connected to a PC so it can receive servos commands

4

You probably need to better explain how the external power supply is connected to the servos, the details of the power supply, and the arduino connections. That many servos will take a large power supply.

5

I used a PC 400 Watts ATX power supply, and it supply's ~5v to the servos

6

I used a PC 400 Watts ATX power supply, and it supply's ~5v to the servos

ok

7

if it's a good old VDU, not a plasma/LED/laptop, maybe the magnetic feld from the motors is upsetting the electrons?

8

I am thinking that there is some type of feedback from the arduino going through the USB.

Yes it is technically called noise and it comes from the motors in your servos.

You need better decoupling on your supply:-
http://www.thebox.myzen.co.uk/Tutorial/De-coupling.html

9

Is this a problem? Can this damage the PC or Arduino if I continue to use it?