I have a Brother HL-4040CDN Color Laser Printer with a Print Unable 3B Error message. I couldn't find a 3B error code in the service manual. I did find a 38 error code that refers to a THM Sensor Failure, but as you can see from the included image the error appears to be 3B. When I turn the printer on, the screen is at first yellow and then turns red. It looks like it is checking the memory. It goes 0M 2M turns red and then shows the Print Unable 3B Error message.