error 1434

I assume you have tried everything here?

iPod: Cannot restore or update in iTunes with error 1415, 1417, 1418, 1428, 1429, 1430, 1436, or 1439

It could be an indication or a damaged or dying hard drive. I would recommend doing a disk diagnostic on the iPod's HD using the instructions given by turingtest2 in this older thread. He also covers what the resulting numbers indicate. Post back those numbers if you need help deciding what route to take from there.

https://discussions.apple.com/thread/3784647?start=0&tstart=0

B-rock