Why my Iphone 3G Only turn on when I conect it to the computer?

Hello Friends: I have an Iphone 3G black 8g that one day shut off itself and don`t turned on anymore. I conect it to the wire to the computer and the only thing that appear in the screen is the sign "Conect to the Itunes", no any emergencies call, no locked and don`t turn on in any other way that connect it to the computer. I tried many many many times to restore it to the original sofware but nothing happen, always come to an error 23 or 16XX. I give to many people here that know a lot of it but they say that could be an a short cut or something else that is diconeted that don`t let it turn on. I am located in Venezuela in south america. I bougth this cell phone from somebody in US but i don`t have the original receipt and the apple people here don`t want to received it to be repair or replace. Please let me know what can I do to repair it or if you know somebody who can be the best repairing this beautyfull tools even in US because I can send it to my brother in Ohio to do something from there.

Thanks for all,

Antonio Valero