MacBook won't turn on

My Mac won't turn on, even when plugged in. The power cord just blinks, and when I used a cord I knew was good, every time I hit the on button, the light on the cord went out, and nothing happened. Any ideas??

Right off the bad i can say that sometimes my charging light goes off while the laptop is still charging. Granted my charger is 4 years old but it still charges the machine perfectly fine. I'm assuming that the laptop was out of batteries that's why its not turning on and your cord is not charging it. Or did the machine shut down and now you cant start it?

Mac back on. Took out the battery for about an hour, pressed the on button with battery out for about 10 sec., and replace battery. Plugged in cord and voile, it works. Have no idea what happened or why this worked

Well sometimes its best not to question it ! Just be glad everything is back to working order!