Shuts off when unplugged, tried new battery, error 21 & 11 restoring

My iPhone 4 suddenly turned off. It asked to be plugged into iTunes. It will power down immediately after unplugging.

I tried to restore / recovery multiple times; I get an error 21 or 11.

I put a new battery and reseated it a few times to make sure it was ok. I've cleaned the dock connector with alcohol.

This was the first time I have taken my iPhone 4 apart, I have not used any unauthorized software, and it was kept very clean. 2 year old phone.