I'm working with an used older Asus Lamborghini VX2 laptop that had a missing power adapter. I got a new power adapter that matches the power input and barrel of the laptop. The power light comes on showing it's charging the battery, but when I press the power button the laptop powers on for a few seconds and then back off again. Nothing shows up on the screen. I've tried unplugging the battery and holding down the power button for over 30 seconds. I've tried powering on without the battery. Any ideas?