There's plenty of causes why your laptop would not power up from the AC adapter and won't charge the battery. Here are some possible causes and solutions to this problem:
Number one, if it's on battery power, the battery is dead or the battery is bad and number two the AC adapter could be bad. Let's roll out number one.
1. Take out the battery, remove main supply, hold power button down for 30 seconds. This will drain the charges in your
battery. Put only power supply in, do not put battery in, turn laptop on, put the battery in.
2. If the solution in no.1 doesn't solve the problem, pull the battery out, keep the battery out of the laptop for this test.
Take your AC adapter and check the voltage with a voltmeter. What you want to test for is voltage. Put the meter at 20
volts DC and take the tip, the power jack tip of your AC power adapter. You hold the black, (the negative part) of your
voltmeter on the outside of the power jack tip of your AC adapter and you put the red (the positive part) of your voltmeter
in the hole in the inside of the power jack tip of your AC adapter. Be very careful not to touch the red and the black part of
your multimeter and the power jack tips of your AC adapter together, otherwise it will create a short circuit.
After doing these procedures, if your AC adapter is good it will output a voltage which ranges from 18 to 19V DC on your
voltmeter, depending on the voltage that puts out on your AC power adapter. If your voltmeter doesn't show any voltage,
probably your AC power adapter is bad or damaged. But if your voltmeter shows up voltage, then we have to go to the
next possible cause why your laptop won't power on.
3. The dc jack on your laptop might be bad, if the dc jack on your laptop is bad or not making a connection to the
motherboard then it look the battery is bad as well, because the battery is now not holding a charge or even taking a
charge. Also, even if your AC power adapter is good and when you insert it to the dc jack in your laptop it could not power
up the laptop because the dc jack is not making a connection to your laptop motherboard in other words the dc jack might
got loose, that's why it's not making any connection to the motherboard. The only way to solve this is that you have to
disassemble your laptop, and take the laptop motherboard out and look where the dc jack is connected. After you found it,
take a file tool and file off a spot on the motherboard where you can reattach the power jack and use a wire to reattach
the power jack to the motherboard.
Hope you find this answer helpful. God bless.http://compunics.blogspot.com/2010/06/podnutz-high-definition-laptop-repair.html