- Test your AC power adapter.
- Take off the bottom cover.
- Test the DC jack and harness.
- Alternative: fix the harness yourself.
Do this first, because you'll kick yourself if you take apart your netbook for no reason. This helps confirm whether the problem is with your netbook or the power supply. Plug it in and use a multimeter (if you have one) to confirm that that the DC output (the cylindrical jack which connects to the notebook) of your AC adapter is putting out its rated voltage (about 19V for the Samsung NC20). If it doesn't, then consider ordering a replacement from http://www.samsungparts.com before proceeding further.
Flip the netbook upside down, and remove all of the screws (except for the screws to the memory access panel). Keep track of which screw went where. Use a flathead screwdriver to pop off the bottom cover. Avoid applying too much force, so as to prevent scratching or denting the plastic chassis.
Here's what the area around the DC jack and harness looks like, on the Samsung NC20:
Here's DC jack and wiring harness look like, when removed from the netbook:
Here's a closeup of the connector which attaches to the netbook's motherboard:
The simplest way to test the DC jack and harness is to plug it in, then use a multimeter to test the voltage at the connector which attaches to the motherboard (shown above). The connector terminals (copper colored, in the picture above) are relatively easy to use for testing, despite being small. For the Samsung NC20, you should see about 19V between the black wires and the red wires. Test both black wires against both reds. If you get a positive voltage for each pairing, and the voltage remains steady when you wiggle the DC connector or wire harness, then your DC jack and harness are probably fine. In this case, the problem likely with something else in your system, and is beyond the scope of this tutorial.
If you don't see voltage across one or more of the black/red wire pairings, or the voltage is intermittent when the DC connector is wiggled, then there's a problem with your DC jack or harness. To order a replacement, go to http://www.samsungparts.com, look up your netbook, and click the "Entire Parts" button to show all parts for the system. Look for a part named "BRIGHTON,WIRE HARNESS CBF HARNESS-DC_JACK", or something similar. For my friend's Samsung NC20 (model number NPNC20KA02US), the correct part number is BA39-00789A, and it costs $11.75. Shipping, handling, and tax brought it to almost twice that, and it was delivered within a day or two.
If you don't see voltage across one or more of the black/red wire pairings, or the voltage is intermittent when the DC connector is wiggled, then there's a problem with your DC jack or harness. To order a replacement, go to http://www.samsungparts.com, look up your netbook, and click the "Entire Parts" button to show all parts for the system. Look for a part named "BRIGHTON,WIRE HARNESS CBF HARNESS-DC_JACK", or something similar. For my friend's Samsung NC20 (model number NPNC20KA02US), the correct part number is BA39-00789A, and it costs $11.75. Shipping, handling, and tax brought it to almost twice that, and it was delivered within a day or two.
Rather than (or in addition to) ordering a replacement DC jack and wire harness, you could opt to repair the existing harness. It helps if you have some stranded 26 AWG (or similar gauge) wire available, but you might be able to simply resolder the existing wires onto the DC jack, if you're careful. Find the broken connection (probably at one of the soldered joints on the DC jack) and repair it. Here was how mine looked after my repair, but before I wrapped it in heat-shrink tubing:
If you found this tutorial helpful, please post a comment saying so! I'd love to hear if anyone found it useful. I suspect that many other Samsung netbook owners may encounter this issue, due to the design and positioning of the DC jack.