Help with iphone 16gb 3g phone

Hi Guys,
i am having bad issue’s with my phone “i will explain wat happened” ok i got an iphone 16gb 3g phone given to me and silly me was eating lunch and some how spilt vinegar all over it and it managed to stuff the main board, so i had a friend replace it with a second hand board that we got from a faulty firmware phone of ebay
Now this is the drama im having, i try to restore phone to new firmware and i get an error (1604) or (1603) i have watched youtube vids and read tuturials and still cant get anything to work, all it says when trying to restore is (prepairing iphone to restore) in itunes then that is it “on the phone the apple logo shows” and a little loader thing pops up at the bottom and doesnt go any further
i have used Ireb (newest version)
tried downgrading firmware
please help guys
Answer #1
Error 1603
If the customer receives an error 1603, and their phone is not automatically placed into recovery mode, it may be necessary to do so manually. Refer to iPhone and iPod touch: Unable to restore for steps on placing iPhone into forced recovery mode.
Also, remove the IPSW and attempt to restore again. If you do not want to remove the IPSW in the original user, try restoring in a new administrator user.
Answer #2
sorry man i didnt understand any of that bro
Answer #3
djeuro replied: sorry man i didnt understand any of that bro
Go in DFU by using iReb… and then try to restore…
One small note.. If you are trying to restore to latest FW (5.0.1) then OK, but if you want to restore to some early released FW you MUST have SHSH Blobs saved and to use TinyUmbrella and TSS Server!
Answer #4
yeah have tried through itunes to restore to newest firmware and it just sits at apple logo with the thinking icon at the bottom until it errors out
Answer #5
and used ireb to put in DFU mode