Servo that reapeats

is there a servo that automatic reapeats itself as long it gets power? would realy help us on a casemod

Can you clarify a bit more at to what you mean by “repeats itself”? The more info you can provide as to what you are looking for the better we can help.
Note that standard RC servos require an input pulse and have no onboard intelligence.

my english is so bad so i tried to keep it short. what i need is a servo that goes 90 degres, then back to 0degres, then 90degres and so on, when the power is turned off, it goes back to 0degres and stays there until it get power again. what do i need to get to have a servo behave that way. easy way. im no programer btw

An RC servo cannot do this without some input signal, which would be a microcontroller.
This is the only product which comes to mind (60 degree travel):
robotshop.com/en/solarbotics … =RB-Sbo-14
You might consider a mechanical system (like a 4-bar mechanism) to get the motion you need.
A solenoid also may be of some use: robotshop.com/en/5v-solenoid.html