My samsung phone has been fully charged. I try to turn it on, it says "initializing," then shuts down. When unplugged, it won't turn on at all. When plugged in, it shuts down, then blinks to the charging screen eery minute or so.

Are you sure it was fully charged before? Could you see the full battery bars?

It sounds like your AC adapter (the charger) has likely gone bad. The phone battery probably wore down, and when you plugged it into the charger, the charger couldn't charge it, so the battery remained dead.

Since the battery is not charged, you can't turn the phone on at all when it's not connected to the charger. And when you do connect it to the charger and turn it on, you get the intermittent charging because something inside the adapter has a faulty connection -- sometimes it works, sometimes it doesn't.

You can easily verify if the charger is the problem by getting a new charger (they're not too expensive) and seeing if the phone will work and/or charge with the new charger.

If the new charger doesn't fix the problem, post again here and we'll go from there, but I think the new charger will take care of it.

Hope that helps!