I don't know if your problem is the same as the one I had with my Samsung printer, but it turned out that Samsung had put microcode in the printer to check the onboard chip for ones with their serial nos. I was using toner from TonerRefillKits.com. They sent me a new chip to put in the printer, and then it worked. I'd check with whoever you bought the toner from to see if that's the problem in your case.
It would seem that about the time you think you understand how something works, some clever devil puts something in like this with "new improved" technology, and we have to go through a new learning experience. Who'd ever have thought they'd put "smarts" in printers.
This machine won't accept aftermarket black toner. I've tried three different kinds. The machine accepts color toner from all three aftermarket sources. But when I put a black toner in, it keeps telling me to replace the toner. The cartridges appear to be identical physically. Does anyone have any ideas on what I can do to make this machine use the aftermarket toner?