Hi, I buy some old NES games online and was wondering how can I spot fake NES or Famicom cartridges and what is the difference between an actually one. I am just looking for some general rules that almost always work. Also how do you spot a unofficial ports, pirate cartridges, bootleg cartridges, and all those illegal stuff. One final thing how can you tell if it was from back in the day or more recent?
You should start from bootgod.dyndns.org:7777 and google "bootleg wiki" for some pirates. Also you can visit Cah4e3 website(blog)
This is a good place to start: http://nintendoage.com/forum/messageview.cfm?catid=8&threadid=122991 You can probably find more info by search NA as the question comes up a lot.
NES games are pretty uniform. Famicom stuff has more variation but the general principles for the pcb's still apply to most cases.
When in doubt, post pics.