i've recently purchased a brand new cortex and downloaded robotc 2.25. i then downloaded the master firmware and the robotc firmware. but every time i turn on the cortex all the motors turn on, even having the usb cable connected doesnt do anything all the motors still turn on. what is going on?

Have you tried downloading one of the sample programs, to see if that changes the robot behavior? If you go to "File" > "Open Sample Program" > "Basic Movement" there are a few programs that will turn on the motors for just a few seconds, as opposed to forever.

Yes I have tried to download a program and there is no change

Can you describe your setup, and the steps you've taken so far? That will help me pinpoint what the problem might be.

Were the Master CPU Firmware and ROBOTC Firmware both successfully downloaded, or did they give you error messages?

Are you programming over the USB A-to-A cable, or wirelessly using VEXnet?

Are the sample program downloads successful? What sample programs have you tried?

Is your "VEX Cortex Download Method" set to "Download using USB Only" or "Download using VEXnet or USB"?

To answer your questions:
yes, the firmware, both, were downloaded succesfully.

i am downloading using an A-A usb cable.

yes, the sample programs are downloaded successfully, iv'e tried both the servo sweep to try and run my servos, and two of the motor programs to run the linear actuators.

i am using the usb only method for download.

i think part of the problem is that immediatly when i turn on the cortex it attempts to bring my servos to the middle of their stroke, i don't know if there is a way to not have it do this. also, i'm not sure that the cortex has the ability to output to all 8 devices at one time. plus, the linear actuators are supposed to run on 12V but the cortex and motor controllers can only handle 7.2V. i think i may need to go with a different microcontroller and motor controllers.