The above is for an example, not advertising.
Enlarge the photo. Shows the Front and Rear view also.
The Center Pin is the Positive connection. The Center Pin has one prong lead going to it.
The cylindrical metal shell, inside the jack; is the Negative connection. As you can see there are two prong leads going to it.
Lastly there are two prongs that stick up also; but only go to the U-shaped metal bracket, that adds stability to the jack.
All prongs of course go down into the motherboard, and are soldered in place. The jack is shown upside down.
You need to wear an ESD wrist strap, and have it's alligator clip attached to a good ground source.
Your body carries Static Electricity. Static WILL fry out (Short Circuit), the delicate hardware components inside a computer.
With an ESD wrist strap, the threat of Static shock to the components is removed.
(And having it's alligator clip attached to a good ground source)
Motherboard removed, the motherboard is turned Bottom side up; so you can access the solder joints, to each one of the DC Power Jack's prongs.
I cut a 6 inch piece of Desoldering Braid, (Solder Wick), and lay 1/2 inch of the tip; across one of the solder joints.
Lay your 25 watt (Or so) soldering iron on top of the braid, JUST until the solder melts.
(No.2 chisel tip for the iron)
All you are trying to do at this point, is try to remove as much of the solder as you can.
The solder wick, (Desoldering Braid), will su-ck the solder up.
Usually the first try gets rid of a lot. You will be leaving behind a thin coat of solder.
What you DON'T want to do is burn the motherboard. Go slow. Takes all day, it takes all day.
If you overheat the motherboard in that solder joint hole's area, you risk lifting a circuit trace up off the motherboard.
[Circuit Trace. Also known as Signal Trace. Think very thin flat copper wires, going all over the motherboard ]
You can also burn the circuit trace hole, (Solder joint hole), and then it won't accept tinning.
(To Tin with solder, is to leave a light coat of solder. A soldering iron, or gun's tip; is Tinned before it is ready to use)
Solder wick tip part that you are using get's 'full', then cut it off so you have a new tip to work with.
Go around, and remove the excess solder, from all those DC Power Jack solder joints.
Removed the excess solder from one DC Power Jack prong?
Allow the motherboard to cool a bit, before going on to the next one.
All excess solder removed from each DC Power Jack's prong, there should just be a light, to slightly heavier; coat of solder left behind.
With the motherboard cool enough to touch, use your fingers to put prying pressure on the jack.
The balls of your fingers grip the jack, and your fingernails work as fulcrums. Gives leverage for your fingers.
Solder iron tip cleaned (Wipe across damp sponge), touch each solder skin joint left behind. You will see you can pry on one side; more than the other; and 1 or 2 prongs should start coming up out of the motherboard.
You can only go so far with them, because the other prongs are still holding the jack.
Allow to cool down some if needed, then go to the other prongs, and heat their solder skin joints.
Keep going back, and forth; or around, and around; until finally all prongs are free from the motherboard, and the jack is removed.
If there is a skin coat of solder left over the circuit trace holes -
LEAVE IT ALONE.
If you try to pick it open, or drill it out with an X-Acto knife blade; you RISK ruining the motherboard.
When you go to install the new power jack, the prongs will be resting up against those holes; and you just touch the solder skin joints one at a time, until the prongs poke through.
See how easy that is? lol!
BEFORE installing the new jack you need to THOROUGHLY clean the solder joint areas. The circuit trace holes, and surrounding area.
I use an old toothbrush, and Isopropyl Alcohol. (Rubbing alcohol)
91 percent is best, but 70 percent will do.
50 percent = no IMHO, because it is 50 percent WATER, and 50 percent Alcohol.
Isopropyl alcohol is EXTREMELY FLAMMABLE!
Use in a WELL ventilated area with NO sparks or flames present.
After cleaning you may find that solder was lifted off, and the circuit trace hole needs to be re-tinned again.
Do so if needed.
DC Power Jack in place, I suggest a LITTLE dab of Rosin paste flux; on each prong to be soldered. (Use a flux paste brush is best)
Helps make that solder stick, and you can make a pretty solder joint. (Should resemble a 'Hershey's Kiss', and be bright, and shiny)
Just examples, not advertising;
More info that may help;http://www.laptoprepair101.com/laptop/2007/12/06/dc-power-jack-repair-guide/
Service Manual (Free),http://www.tim.id.au/blog/tims-laptop-service-manuals/#toc-gateway
Go to - Gateway 400. (400 in blue) Scroll across, click on -
(It's a PDF file. The computer you are using now has Adobe Reader on it, which uses PDF files.
After you click on the file name (450ROG), it may take up to 30 seconds, before the first page comes up )
For additional questions please post in a Comment.