The laptop power light flashing erratically and the battery charge light blinking on and off when AC adapter is plugged into the laptop.

Possible cause:

1. Power jack failure.
2. AC adapter failure.

Possible troubleshooting steps and repair solution:

If it happens only when you move the adapter plug inside the power jack, it’s likely that you have a problem with the power jack inside the laptop. The power jack has to be resoldered or replaced.

If it happens even without touching the adapter plug, the problem could be related to the faulty power adapter.

You can test the power adapter with a voltmeter and find out if the ouputed voltage is correct. If the voltage is not correct, replace the adapter.

But don’t trust that even if the output votage matches specifications. It’s possible that the power adapter doesnt’ work correctly under load. Test your laptop with another known good adapter. If the laptop works fine with another adapter, your power adapter is defective and has to be replaced.

The laptop switches from AC power to battery power even when the AC adapter is still plugged into the laptop. The AC power light goes off but the laptop keeps running from the battery. If you adjust the position of the power plug inside the socket, the power switches back to AC.  The problem is intermittent. Intervals between the power failure may vary.

Possible cause:

1. AC power adapter failure.
2. DC power jack failure.

Possible troubleshooting steps and repair solution:

First of all, test the AC power adapter. It’s possible that the power cord on the AC adapter is damaged. When the cord is moved, power stops coming from the adapter to the laptop and it starts running from the battery. In most cases the damage occurs in the area where the cord is connected to the power plug.

You have a couple of options here:
1. Test your AC adapter with a voltmeter. Make sure the power is not cutting off when you move the power cord.
2. Test your laptop with another known good AC adapter.

If you still experiencing the same problem with a new AC power adapter, most likely your problem is related to the power jack inside the laptop. The power jack is a socket where you plug the adapter.

It’s necessary to remove the motherboard and take a closer look at the power jack.
1. Resolder the power jack if it’s not making good contact with the motherboard.
2. Replace the power jack if it’s broken.

The laptop is completely dead. When you plug the AC adapter and press on the power button, nothing happens. The laptop has no signs of life at all. None of the LED lights is working.

Possible cause:

1. AC adapter failure.
2. Power jack failure.
3. Motherboard failure.

Possible troubleshooting steps and repair solution:

1. Test the AC adapter with a multimeter. It’s possible that you have a failed AC adapter. If you don’t have a multimeter, test your laptop with another known good AC adapter.

2. It’s possible that power jack (socket where you plug the AC adapter) is broken. Remove the motherboard and take a closer look at the power jack. In some cases you can fix the jack by resoldering it on the motherboard. In other cases you have to replace the jack with a new one.
Using a multimeter, test if the power goes to the motherboard through the jack.

3. If replacing the AC power adapter and jack on the motherboard doesn’t help, most likely you have a bad motherboard. Replace the motherboard.