My car won't start

I have a 1999 Buick LeSabre that will not start. We drove it around, came home and then decided to go out again and it just would not start. We have a new battery that checked out fine and the started also checked out fine. All the dash lights come on and when you turn the key it does make a short humming sound, then nothing. This has never happened before. I did have a problem a couple of months ago with the automatic doors locking on their own but I don’t know it that has anything to do with the problem now. We are at our wits end as to what to do.

How did you check out the battery?

I would suggest removing and cleaning each end of each battery cable and securely reattaching them.