When I work on a laptop, the first thing I always check is for proper voltage output.
Many times I have had customers bring only their laptop in and think their battery is bad - then I plug in my universal adapter and the battery charges fine.
The customer takes the laptop home and then brings it back, still thinking their battery is bad.
I always try to get them to bring the power adapter with the laptop so I can test the whole system.
Voltage will vary so always check for your model's correct voltage.
Most laptop's power adapters put out around 19.50 volts.
Let's get started.
1. Get out your multimeter.
2. Attach red lead to the center of the jack.
3. Hold black lead to the outside of the jack.
4. Read the voltage on the multimeter
TIP: While reading the voltage move the cord around the power jack and watch the reading on the multimeter. If the voltage remains the same then the power adapter has passed the basic test.
If the numbers on the meter go up and down then there is a break in the cord somewhere. You can get a new one or you can repair the area.