I got the same problem as yours, I sent a email to ems (which the manufacturer of the cart) they say it might be I got a defected cartridge, and ask me to send it back to them and they will replace it for free, but I have to pay the postage. Is that any help? Btw: I haven't sent it back to Hong Kong, cos just don't bother, I got a ram cart from ebay at the end.