Do You Need A New Adapter?
Frayed Power Cables
As notebooks get older, it's common to encounter fickle power adapters. Over time, plugs and connectors start exhibiting quirks. We've seen cords that have to be held a certain way to maintain a connection. We've seen others that simply stop charging the battery altogether. Few of those problems are do-it-yourself fixes. More often, the easier alternative is simply buying a new adapter.
From there, you can buy a straight replacement from your system's vendor. Or, you can go with a third-party solution. With a replacement, you know what you're getting. But a third-party's solution might include more features. It's a tough call, really. Before you go the third-party route, know that using non-factory equipment could very well void your machine's warranty, if it's still covered.
Asus says that, as long as the third-party adapter supports the right input/output voltage and power specs, your warranty remains intact. If the charger doesn't closely match the original adapter's specs, though, and damage occurs, the company may not honor your warranty. The reasoning is sensible. It would argue that the damage might have been caused by another company's power adapter, though it isn't clear how closely the third-party hardware would need to come to Asus' original equipment.
According to Dell, "all Dell-branded power adapters have to pass the Dell qualification process and necessary system-level certification." This means that only power adapters supplied by Dell or included with a Dell-branded solution are covered under the company's warranty policy. If damage occurs as a result of using a third-party adapter, your notebook isn't covered.
So, Where's The Problem?
Most AC adapters feature an LED built into the power brick. As you might imagine, this serves an actual purpose. If you plug in your notebook and that light doesn't turn on, something is wrong.
Most AC adapters come as two parts: the AC cable and the DC power brick/output cable. If you aren't getting power, and you don't have an LED or a two-part adapter, there are some steps you can take to check for damage. Obviously, you should only follow these steps if you have experience with power equipment and already know what you're doing.
First, set your multimeter to measure AC voltage. If your power adapter comes as two parts, disconnect the AC cable from the power brick and make sure it's plugged into the wall socket. Attaching the test leads to the AC cable, you should get a reading close to 120 V. Be careful when you do this; the two test leads should never come in contact with one another as current passes through them.
In order to test the DC side, set the multimeter to measure DC voltage, similar to the picture above. After reattaching the power brick and AC plug, check the voltage by touching the inside and outside of the connector.
Usually, you'll find a diagram on the wall wart that illustrates the positive and negative contacts. If your adapter doesn't have this, most manufacturers expose negative polarity on the sleeve and positive polarity in the center. If your connector includes a center pin, ignore it. Dell uses that pin to transmit a signal that verifies whether the adapter is one of its own or not. Other manufacturers use it to center the plug. Most of the time, the inner and outer sleeves are the parts of the plug that actually carry current.
If you aren’t getting a reading on the AC cable, you might just need a new cord. An auction site could be your solution there. If you aren’t getting a reading on the DC side, there's a good chance that you need to replace the entire brick.
