Hi,
I bought a iphone 3gs from my friend but it was badly damaged with a broken screen and a case which the buttons didnt work.

So I bought a new white case, new battery and a new white screen digitizer.
So when I put all the parts together I had the white screen of death.
When I tried to restore it I realised the new battery didnt allow the iphone to restore as the iphone was a newer type of the 3gs model and the battery was an older one. I was heard that iFixit had a battery that would work on all models so I purchased it.
As of Now, I have installed the new battery but its still constantly on the white screen of death no matter what I try and do.
Any suggestions?

Thanks.

Worth mention that in some cases, a white/green screen is just indicating that the battery is dead and charging, and doesn't have enough power to boot the phone. How long have you left the phone plugged in?