Iphone 3G Unknown History Faulty

Hey ive recently got with a new partner and has found out im technicly gifted and asked me to fix her iphone 3g. its been dropped in the toliet thrown against the wall and thats all i know. cured (I believe) the water damage and replaced the LCD and Digitizer perfectly. this is where me not knowing the history fails me. it wont restore. either in DRU or recovery. either way get 1603/1604 error's with an odd 23 thrown in for good measure.

hopefully someone could help me solve this and trying to give you as much information i can this is what happens when i attempt to restore.

Attach, DRU, click restore (with old and latest firmware), verafies with Apple then.

Preparing to restore iphone (Computer regesters 1 Disconnected device, 1 Connected device then finally 1 device disconnected) and thats as far as i can get.

i am attempting to do all of this whilest the LCD and Digitizer is not in place but the plastic faceplate with the home button is attached completely. any help or advice would be very apreachated. and many thanks in advanced.

Chris

Just to add i have tried it in EVERY USB slot i have with no luck i have deleted itunes info in the roaming/itunes computer file (the ones your supposed to) and even download the new firmware 5 times havent got access to another computer and have used "iREB" with no avail.