[Tutorial] - Fixing a bricked system

[MrTomWins]

I can confirm this method works, hehe.

Couple of additions. If you are getting garbage output in Putty, check your soldering. Even if it looks good, something could be wrong.
Using a cheap ebay USB-TTL, a little blue light should be on when connected properly.
If Putty is showing nothing, check soldering, then try swapping the tx and rx over. So if tx-tx and rx-rx doesn't work, try tx-rx and rx-tx.