I am not sure where to post this but here goes. Compaq PresarioC500 laptop running windows 8.1. my nephews laptop. was doing a fresh install and updating as neccessary. looked good, took it back to my nephew and was gonna show him how it looked started up-loaded windows fine and died. light on front showing it was plugged up to power is now blinking real fast. will not turn on. so i buy a new power cord and tried it, no change- so i get brand new battery yesterday, installed it, started right up-3 little lights showing solid green instead of flashing. was installing a few apps for him and just shut down after 15 mins. will not come back on, flashing light showing where it is plugged up to charge. Help me please.