Remove battery and power to reset POST

When there is a power surge some laptops stop working. The answer might be when your computer turns on there is a checksum that is done by POST or power on self test. Different tests are done to check the integerty of the hardware for example by counting RAM. A power surge can confuse this integerty check. To correct this, remove the battery and remove the power cord from the computer. This would reestablish a baseline by scanning for new hardware.