Hi, I'm Wes. I can help with the issue.
Sometimes the metal contacts inside the printer area where the toner cartridge sits becomes dirty and needs to be cleaned.
Use a damp cotton swab with water or Windex to clean the inside of the toner cartridge area to ensure the metal contacts are clean.
Then try to re-insert the toner cartridge.
Also, check here to see if you are inserting the toner cartridges correctly: http://support.brother.com/g/b/faqend.aspx?c=us&lang=en&prod=hl4570cdw_all&faqid=faq00000065_052
Let me know if you need additional help so I can assist further.Also, please rate my answer below so based on your satisfaction.Thank you.
It sounds like it needs to be thoroughly cleaned as some sensor may be dirty.
If you have a compressed air can to blow out the insides of the printer to clean the dust and extra toner (do this outside).
It could also be the toner cartridge. What model is the toner cartridge?
That is the correct toner.
The printer will most likely need to be cleaned using a air can and clean all the metal contacts inside the printer.
Printers usually need to be serviced to work properly.
Let me check if there is one.
This one should do the trick: