To clarify, Brother is deploying toxic firmware to their MFC-3750s. I don't think this is widespread (yet). I did see requests to roll back firmware on a MFC-L3

To clarify, Brother is deploying toxic firmware to their MFC-3750s. I don't think this is widespread (yet). I did see requests to roll back firmware on a MFC-L3770CDW so other 37xx models may be at immediate risk. I did see posts about HL-L3290CDW and MFC-L8900CDW with the same No Toner symptom but it wasn't clear they ever had firmware updates. From what I can tell from your link, the OP there had a HL3070CN. It doesn't appear that he updated the firmware or ran into any No Toner errors. He was sharing reports about the 3750. My similar HL3040CW takes 3rd party cartridges (orig firmware). My vibe is Brother is test-fouling the water to see how it goes. For my part, I'll research how block firmware updates (not all models have an auto update to disable, IP & url blocking might block driver downloads. We shall see).