Brother MFC-L3770CDW Toner Fix

I recently powered down my Brother MFC-L3770CDW printer after it had been on probably for a year. When it came back up, I had a NO TONER error (not a "low toner" error). The toner was definitely nowhere near empty, but the printer simply didn't recognise the toner. I pulled the cartridges out and put them back in, but that didn't help. These toner cartridges are not the genuine Brother brand…