One of my ex-flat mates is not so computer savvy and found me with her problem the other day. Her laptop wasn't charging unless she held the charger's connector firmly in place, and she was concerned if this quick switching was killing the motherboard in her laptop.
It was a rather old Fujitsu-Siemens A1650G notebook with a 3300+ Sempron processor and 512MB RAM, and the battery held on for about 40 minutes fully charged. She also had some weird shut down problems which she thought to be related to either the charger or the battery. I told her to look around and see how much it costs to fix the DC jack because I was sure the problem was related.
She even told me that her roommate tripped in the cord, so that gave me some extra confidence, in my opinion. She took the laptop and asked a few computer repair shops along the road here in London and the lowest price they told her was 70 pounds (more than a hundred dollars), which I found to be ridiculously high for the complexity of the problem.
We headed to town and bought a tin and a soldering iron with a pointed tip. We also got a screwdriver set so that I could disassemble the thing. When I took the laptop apart at first, it took me three hours because I didn't want to break any of the small plastic parts that hold these cheap notebooks together.
I removed about twenty screws and put them into a bowl, but it didn't want to come apart, so I watched a few videos on YouTube about it and found one where a Romanian guy shows to take these things apart. He took another approach, which worked just fine for me as well. I thought I had to be careful when disassembling a notebook, but I forgot that I also had to be firm. Took a big screwdriver and popped the black panel in front of the screen, taking care of the small plastic pieces but applying enough force.
When it was off, I had access to the keyboard, which pops out just fine if you push the left and right edges to the middle while pushing the whole thing towards the screen. From that point, the disassembly was straight ahead, and about half an hour later, I could see the root of the problem. Her flat mate pulled the charger so hard when she tripped that two of the five legs were completely missing, they fell off, and one leg, the one in which the middle pin ended, was one of them.
It was grim, so we ordered a replacement connector for about 5 pounds plus two for shipping. While the one I ordered looked exactly like the one in the notebook, it turned out to be the exact mirror image of it. First, I thought it wouldn't fit, but looking at where the legs are connected inside the connector, I figured I'll get away with putting it in from the other way around into the motherboard.
I removed the old broken one in about two hours. The legs still in the soldering point took me the most time to remove as the soldering iron didn't work the way I expected it would. It taught me that a cheap soldering iron is not always the best possible solution.
Installing the DC connector went quite easily, and with the routine I had from disassembling the laptop two times before I put it together in twenty minutes to see if it charges. It did; however, the pin was a bit firm because it was bigger than the original. The charger fits it well, though, so it's all well.
I also found that the shutdown problems were caused by inadequate thermal greasing and a bend in the heatsink. Using an alcoholic cloth, I cleaned the surfaces, added the grease and using two folded pieces of paper under two of the springs, and I managed to offset the bend. Note that laptops have IHS on the core, so you must be careful while taking the cooler off or putting it back on to avoid chipping it.
The whole process with the screwdriver set, soldering iron, new connector took me about 20 pounds and five hours, and the next time I'll have to do it, it will cost only about 7 pounds.