My MFC9340 has a drum error again. Every time I change the toner this happens. Today I took the cartridges out to shake them and slide the cleaner wires because it was printing lightly. After reinstalling it indicated a Drum! error. I can slide the green drum corona tabs till the cows come home with no help. In the past I've cleaned the corona wires with a Qtip (as seen on You-Tube) with success but it didn't work this time.\n\nUnfortunately the printer doesn't indicate which color has the problem. Today I pulled out the cartridges one by one to isolate the fault. Even with no cartridges installed it still indicates a Drum! error with instruction to slide the green tabs. Can anybody tell me what display message they get when one or more toner cartridges is removed?\n\nSeveral times I got the message to go away by leaving the printer powered off overnight. Powering off for an hour or so didn't work. I guess I'll do that again.\n\nLast year I spent several hours on the phone with Brother support and they finally said I need all new drums. Later I tried the Qtip cleaning and it came back to life.\n\nDoes anybody have a suggestion?