Christmas light trouble?

So I got this Christmas tree from my mother in law and the lights are like built in but when we hooked it all up some of the sections of the tree blink with lights, some don't come on at all and like 1/4 of the tree just stays on like I pictured the tree to do. Is there any way to fix this or should I just get a brand new tree? I just thought it was cute to have the tree my hubby grew up with :/