every time I plug the adapter into the wall the noise happens… Laptop will not charge.

The first thing you need to check is the LEDs light of the power cord. Led is normal on power cords to show the status of the part. The HP Pavilion DV7 AC adapter might be defective if if the LED of the ac adpater is not lit and the cord is firmly seated in both the transformer and the wall outlet.

If that’s the case, what to do if the HP AC Adapter does not work? Here are the steps for you to follow and verify where the problem is. (Please note that this also works for hp probook 4520s Adapter and other laptop adaptors)

  1. Verify that the AC adapter brick is receiving power.
    • Shut down the laptop and unplug the HP ED495AA adapter from the system first and then from the power socket. Wait 5 seconds.
    • Plug the adapter directly into the wall socket, bypassing surge protectors, UPS units, or extension cords. The hp DV5 adapter LED should produce a steady green light.
    • If you do not get a green light, try the adapter in another wall outlet in another room or verify that the first outlet works with a lamp or hairdryer.
    • You can also isolate the power problem to a bad adapter by swapping it out with a second HP DV4 adapter – such as one for use with the port replicator.
  2. If the adapter LED lights, check the computer for bad connections.
    • Examine the system power socket to be sure it does not have any bent, missing, or pushed-in pins.
    • Plug the adapter connector directly into the HP laptop, bypassing surge protectors, extension cords, etc. Be sure that the adapter connector fits tightly into the computer’s power socket.
  3. If you have access to another computer like yours, try your adapter on it or its hp pavilion dv4 adapter on your computer.
  4. If your HP notebook is no longer under warranty and the HP laptop power cord does not respond to troubleshooting, you may purchase a new AC adapter.