Power surges occur when an electrical charge is sent suddenly through the lines. These cause spikes in the typical power flowing through an outlet: power and phone outlets. Weather is one of the most common causes of power surges, though problems with your electric company's equipment and high powered electrical devices can also cause power surges. When a laptop is the victim of a power surge, the effects range from no damage to inoperable.
Charger And Battery
The charger is what supplies power to your laptop and is the first thing to be hit. If you notice your battery no longer charges or takes much longer to charge, your charger is probably damaged. In addition to the charger, your battery can be damaged as well. It may run down quicker or not hold a charge at all.
System No Longer Boots
One of the worst things that can happen to a laptop during a power surge is the motherboard being hit. If the motherboard takes the brunt of the electrical surge, your laptop will no longer be able to boot. Your motherboard controls your BIOS, which is responsible for hardware and operating system start ups. Your motherboard also controls your fan and every internal portion of your laptop.
A low voltage power surge may result in a sluggish system. This typically means your hard drive was hit. Bad sectors on your drive result in longer boot times, slower application loading times and files opening slowly or not at all. You can run a check disk scan from the command prompt to check for bad sectors.
If you have your laptop connected to wired network or a phone line, a power surge, especially weather related surges, can damage or destroy your modem. For high speed cable modems, this can damage your cable modem and internal network card. If you have problems connecting to the Internet after a surge, the modem was affected by the surge.