There are a number of reasons why your notebook computer may stop powering on, the most obvious among these being a power issue. However, even that can be somewhat complicated to diagnose, as power issues can come as a result of a bad outlet, bad charger, bad battery, or a damaged DC jack. If you think your problem may originate from the DC jack, there are a few tests you can run to see if it does in fact need to be replaced or repaired.
First off, you’ll want to remove your battery. If your laptop is only receiving intermittent power, your battery will kick in and mask this problem, causing you to miss some important symptoms. Power on your laptop and basically start wiggling everything. It sounds silly, but it really is an easy and effective objective test. Start from your charger’s cord where it connects to the wall, all the way to wiggling the adapter in your DC jack. If your laptop shuts down, you have found a bad connection. If it occurred when moving your adapter’s cord, you have a bad adapter. If you see the charging/power light flickering or flashing, you may have a DC jack issue.
To verify further, try a different AC adapter, or try that adapter in a different compatible machine. If you don’t have a spare adapter or machine around, you will have to use a multimeter. Check the connection inside the jack to see if you get a reading. Attach the multimeter to your adapter’s jack, and then wiggle the cord behind it. If the meter jumps or fluctuates, your adapter is likely bad. You can also attach an Ohm meter to your laptop’s DC jack. If it is seated properly, you should see some brief continuity readings. If you don’t, your DC jack may have come unseated from your motherboard.