If the computer suddenly fails to startup properly, perform a hard reset as the first action. Performing the hard reset will correct many problems. If the computer still does not start properly, select your symptom from the list below to guide you to the recommended corrective actions.
1. Disconnect all peripheral devices and remove all USB devices and SD media cards.
2. Disconnect the AC power adapter, remove the battery, and then press and hold the power button for at least 15 seconds to drain all residual power and restore default startup settings.
3. Reconnect the AC power adapter (but do not insert the battery), press the Power button, look for glowing lights near the caps lock and num lock keys, and listen for sounds of a fan or other moving parts turning.