Counterfeit GBA Carts

From PHWiki

How to recognize a genuine GBA cartridge

Counterfeit pirate GBA carts are very common, particularly in parts of Asia (where genuine carts can be very hard to find) South America, eBay, and even American second hand stores. Luckily there is a surefire way to recognise a genuine cart. At the edge of the cartridge connectors the word "Nintendo", a copyright year, and a serial number is printed. This is never present on counterfeit carts, or flash cards for that matter. It can easily be spotted by holding the cartridge under a lamp and tilt it to look inside. (You do not need to open the cart, this was only done for clarity in the photo.)

How to avoid counterfeit pirate GBA cartridges

They are extremely common on eBay, especially from Asian sellers, but also from the US and everywhere. The cart being too cheap ($5...) is a big redflag, as is bare carts with no box or manual. But many counterfeit carts come with box and manual as well, so it's no guarantee.

Counterfeit carts have also been known to pop up at reputable retailers all over the world in the second hand section.