Did you try the old "wipe down the cartridge with rubbing alcohol trick"?
If you tried that and it still doesn't work, you might want to think back to see if there was any possibility that static electricity got to your chips. I've heard that you can take rubber eraser tip to 'rub' the contacts of the chips to get them working again, but have yet to confirm this.
So I would recommend to try wiping the chip first, then do the eraser trick with rubbing trick together if it still doesn't work. If you still are encountering problems, please e-mail us with your contact number at firstname.lastname@example.org
with your order number and we'll give you a call to see what we can work out. Hope it works out!