Alright so i have two Compaq Evo N610C laptops and both of them work fine whenever on battery power; however, on one of them whenever i unplug the power cord it makes a loud whining noise as if a fan was touching plastic or something then just compeltely shuts off. On the other laptop nothing happens, battery works fine.

Also, whenever the laptop is off and the battery is plugged in i can hear a small whizzing sound coming from around the battery.

Does anybody have any ideas on what the problem might be?

Thanks!!

I would guess that your battery has died.

Well that's what i was assuming, but when i put the battery in the other laptop it works fine, works on battery power also,

In that case it seems likely that there is a loose/bad connection associated with where the battery plugs in.

Alright i'll check it out, thanks for the help