I got a missignatured ATmega328-PU. How can I fix that?
While browsing sparkfun, i have found several news posts that show their struggle with mislabeled chips. Here are a few:


https://www.sparkfun.com/news/350
https://www.sparkfun.com/news/384
https://www.sparkfun.com/news/364


Sparkfun had received a questionable shipment if ICs from a new seller in china. They decided to test them before sending them into production, and none of their test boards worked. Using nitric acid, they were able to remove the case of the ICs and fould a hunk of metal that looked like copper.

In another article, they dissected some suspicious ICs from Atmel, and found an ON semiconductor silicon wafer inside. The chips were not functional ATmegas, but they did have silicon, unlike the other ones.