Battery dead? I've seen several laptops that would do this. It's been a broken charging jack (so even when on AC power, it was still running on battey), bad charging circuit, or bad AC adapter. In most cases, it was just the laptop running the battery down to dead, and when the customer would power it on, it just came on long enough to show a bios splash screen, and then power off. You might verify that a charging light or AC power light comes on when the adapter is plugged in. If it does show it's charging and on AC power, and the problem persists, the problem could be deeper. Check that, and get back to us and we'll go from there.