There are two fuses on the board. One right next to the charging port and one beside/half underneath the wifi module. Marked F1 and F2. Some people say it's a shot filter coil (the square block next to the port with four pins), others say it's a broken charging IC.
Does your charging light come on for a short time or isn't it showing anything at all?
I have the same problem right now.. There is voltage on the fuses and on the charging pins but it doesn't want to charge the battery..