My notebook has either a bad power jack or a damaged connection between the power jack and the system board

I have a Dell Latitude D600 notebook with either a bad power jack or a damaged connection between the power jack and the system board. The power converter will connect and run the machine, and the battery will charge, but the connection is flaky–it will go out and the battery will run down without me noticing until it’s dry, and if I move it and plug it in again, it takes a lot of jiggling to get a connection. I’ve tried it with a known good converter–same problem.
I would like to do as much of the legwork as possible–preferably everything short of the actual resoldering or replacement–to cut down on how much I impose on my friend who can do that.
It’s been ages since I used a multimeter, but I can look it up and refresh my memory. I can get the system board out safely, etc.
How do I visually inspect or otherwise test the system to determine if the connection from the jack to the board is bad or not?
I found a source to order the jack if I need one.
What do I need to know about the model-specific pin setup (if you can tell me) to either fix the connections or install the new jack?
Again, I can do everything but the actual soldering, since I’m not experienced with that and I’m all thumbs.
I *don’t* remember much of my basic electronics, but if you tell me in tech-ese I can either figure it out or get somebody to translate it.
Thanks in advance for taking time reading this, and a thousand thanks if you can help me.

First, you’ll have to remove the system board from the notebook and take a closer look at the power jack, use a magnifying glass if needed. Examine the jack pins. If the power jack pins are broken (very unlikely), you’ll see that, you will not need a multimeter. In this case you’ll have to purchase a new power jack and replace the broken one.
In most cases the power jack isn’t broken, it just doesn’t make a good contact with the system board. Examine the place where the pins connect to the system board. Most likely you’ll see a crack in the solder that holds the positive pin in place and the pin itself will be black because of oxidation. In this case you’ll have to resolder the jack. When I repair a problem like that, I usually complete the following steps:
- unsolder the power jack from the system board. Use a solder sucker to remove the solder. This step requires some soldering experience. If you are not careful enough, you can damage soldering pads on the motherboard.
- clean up the power jack pins and apply a coat of fresh solder on all pins
- clean up the soldering pads on the system board and coat them too
- install the power jack back on the system board and solder it
You don’t need knowledge of electronics to replace the power jack, but you’ll need some soldering skills. If you’ve never soldered before, find someone who can help you. Don’t do it yourself or you can damage the system board.