subject: Illustrate Work Process of Laptop AC Adapter [print this page] The most commonly seen laptop AC adapter includes a small black sealed box, with one wire to the computer and another side to the wall. There is usually an LED light on the corner of the adapter. As this Dv5135nr AC adapter, you can see the light at the bottom of the adapter, which tells you that it is on. What does this tiny light work for? And how it co-works with the AC adapter? the following information will be useful.
For this small Dv5135nr AC adapter, what does it do? Just connect the current to the laptop? It lowers the voltage from 120 volts AC to typically 13V~19 V DC. It will be marked with the exact voltage. It often includes an automatic circuit breaker or overload detection. If this gets tripped, you can generally reset it if you unplug it from everything for a few minutes.
You can measure the voltages on your AC adapter with a multimeter. When it is unplugged from the computer but still plugged in to the wall, it is normal to see that the voltage may be 1 to 3 Vs higher than the printed output.
AC Power adapter LED is off when you plug the adapter into the wall but not into the computer
Has it been overloaded? Is the power strip turned on? Or is the outlet working? Is the cord from the adapter to the wall fully plugged in on both ends? Your adapter may be fried- try borrowing an identical adapter from a friend and seeing if that one will work in its place (but do not plug it in to your computer, or you might fry your friend's adapter)
Check output voltages with a volt meter or a multimeter: For those of you with circular connectors, your task is easy. Measure the voltage between the inside and the outside. A diagram on the adapter's label will tell you which should be positive and negative.
All these should be done under a safe circumstance. If you have no idea of the circuit, don't try this. And my Dv5135nr AC adapter has been destroyed by my curiosity. So be careful when you try to handle the adapter problem by yourself.
