Daughter last used laptop on battery power and ran id down completely until computer shut off. She plugged in the power cord and it would not come on when pressing the power button. Laptop was plugged in overnight and this morning same issue - the power light just blinks five times when you press the power button. This is the same behaviour whether plugged into power or not. I've tried holding down the power button. Tried with battery removed and A/C power, but then no light comes on at all. I've tried removing the battery and A/C power, holding the power button down for 30 seconds, then install battery and plug in A/C power, but no difference. I tried a different A/C power adapter and no difference. Any ideas?