Your symptom indicates a power supply problem.

The battery lights are the two yellow LEDs next to the green power light:

When the battery is charging, the battery light flashes twice.

When the battery is discharging, it is on solid.

When the battery is charged, it is off.

Eliminating some possibilities:

• Test your charger to make sure it's putting out 19.5VDC. If it doesn't seem to be working, see if you can test your computer with another one.
  
  

• If your machine runs on a charged battery from another computer, we can probably fix it. Go to shipping.
  
  
• If you can sometimes get it to start up and run normally by pressing the AC plug a certain way, but wiggling the plug makes it suddenly stop, we can probably fix it. Go to shipping.
  
  
• If your computer exhibits any other symptoms, our quick fix won't help.