fv 274 av dc jack

I have a dv 7 fv 274 av and think it may be the problem and want to make sure not to get the wrong part . When plugged in if I play around I can get a light showing it is on and charging, the slightest movement and the light goes out. If I try to power it up the light goes out, When I don’t touch it and the light goes on the battery charge but not completely. Somehow the os is now corrupted and I can not get the computer to stay on long enough to do a repair of the system. My thought was a correct replacement of the jack might lead to be able to use the machine again.