My monitor turns off after 15 seconds says out of frequency

[trishad6]

Hello,
my gatway monitor works for 15 seconds and then shuts off. It has a message saying it is out of range and then counts down from 15. Does anyone know how to fix it. Also my tower is a an HP Compaq.

 

[Dark Lord of Tech]

The message is from the monitor itself, not from the computer.

It is advising you that the monitor refresh rate or scan rate exceeds that which the monitor can handle.