Car started when jumped, but after installing a new battery it still won't start

battery / alternator

I was gonna wait and let mame answer...

Have ya checked all those connections yet? The ones at the starter and the negative at the frame?

My bad

I called a guy on craigslist who checked the terminals and said they were too loose. He used an old trick, flipping the terminals upside down and hammering them in and tightening them. Started right up.

groovy.