If you have used the same non Epson cartridges both times and the first time they worked then it is probably a problem with the second batch of cartridges you bought, I suggest contacting the supplier you purchased them from and see if they can help you or possibly replace the cartridges.
The quality of non genuine products can vary a lot depending on where you buy them from so always be careful when doing so, check for ratings and make sure you have some sort of guarantee.