Brother HL-2240 Printer Drum LED is still on or flashing after I replace the drum unit with a new one.
The Brother HL-2240 Printer Drum LED as shown below will continue to be on or flash if the drum counter was not reset when you

As with any sophisticated office product, errors may occur. If this happens, The Brother MFC5895CW Printer identifies the error and shows an error message. The most common error and maintenance messages are shown below.

This post refers to five LEDs Back Cover, Toner, Drum, Paper, Status and two buttons Job Cancel and Go on the Brother HL-5340D control panel.

Brother HL-2230,HL-2240 ,HL-2240D ,HL-2242D ,HL-2250DN ,HL-2270DW LED Control Panel Error status refers to four LEDs Toner, Drum, Error, Ready and Go button on the control panel.

Troubleshooting the Brother HL-2140 HL-2150N HL-2170W with three LEDs : Toner, Drum and Error, and a dual function Ready LED & Go button on the control panel.

Checking the print quality the Brother MFC-5890CN ,MFC-5895CW ,MFC-6490CW printers
If faded or streaked colors and text appear on your output, some of the nozzles may be clogged. You can check this by printing the Print Quality Check Sheet and looking at the nozzle check pattern.

Brother MFC-5890CN ,MFC-5895CW ,MFC-6490CW Error ink Empty.The Brother MFC Multifunction Printer is equipped with an ink dot counter. The ink dot counter automatically monitors the level of ink in each of the 4 cartridges (LC61 :LC61B,LC61C,LC61M,LC61Y).