I had an iPod touch 4th generation I was told was no good, and it had a broken screen and the Home button was missing. I connected it to my computer, updated the iOS and loaded some music on it and it played fine. So I ordered a new screen and home button.
Since this was my second iPod touch that I attempted to fix (the first I ended up taking in to get fixed) it went better than my first try. I got the screen all connected and everything but the screen put back where it all belonged and turned it on. I got the white screen of death.
After much frustration, I reset the device by pushing Home button, the power button and the up volume button all at the same time. It booted to the set up screen so I turned it off, put the adhesive strips on and the screen on. I turned it on and got the white screen of death again. This time it would not reset at all.
Before you start make sure you're in a good frame of mind. There's lots of tiny parts and screws, along with fragile boards and connectors. It's not a hard fix (if things go well), just a bit tedious working with the small parts.