I would first look to see if the wall adapter is making a good connection with a plug known to be "hot", then make sure the phone is connected cleaning to the adapter by looking into the connection port. Look for any grime or lint that might obstruct the connection. These are the two easiest problems to solve. If it isn't either of them, removed the battery and check that it is making a good connection. I'd try this a couple times just to be sure. If it isn't either of these problems that means the problem is internal. The phone has two boards inside it. The mainboard holds the power connection and it would be my assumption that this has been damaged. It has happened to my personal treo once. The only fix for this is replacement of the mainboard. It isn't terribly difficult for soneone who is experienced but it is very invasive. Sorry for the bad news if this is, indeed, the problem!
Answers & Comments
I would first look to see if the wall adapter is making a good connection with a plug known to be "hot", then make sure the phone is connected cleaning to the adapter by looking into the connection port. Look for any grime or lint that might obstruct the connection.
These are the two easiest problems to solve. If it isn't either of them, removed the battery and check that it is making a good connection. I'd try this a couple times just to be sure.
If it isn't either of these problems that means the problem is internal. The phone has two boards inside it. The mainboard holds the power connection and it would be my assumption that this has been damaged. It has happened to my personal treo once. The only fix for this is replacement of the mainboard. It isn't terribly difficult for soneone who is experienced but it is very invasive. Sorry for the bad news if this is, indeed, the problem!