Car won't start on 1996 Chevrolet Lumina

Car won't start. Makes no sound; radio works and lights are bright. Try to start off and on for approx 1/2 hour; car starts after approx 1/2 hour. Runs good for approx 7 days then won't start again; same as before.

Asked by for the 1996 Chevrolet Lumina
1 answer 1 comment
It's possible that the starter is starting to fail. You could check to see that there's battery voltage when your assistant turns the key to START while you have a meter or testlight on the smaller START wite at the starter. If there's 12 volts at the START wire and the starter isn't turning, it's defective.
Here's a directory link for you:
Yes, this answer was very helpful. I am proceeding to check the starter.