From: http://h10025.www1.hp.com/ewfrf/wc/document?docname=c01796821&cc=us&dlc=en&lc=en&os=4063&product=83027&sw_lang=

  Deskjet 6122 and 6127	= Deskjet 990c

How to Reset the Brother DR250 Drum?

http://ezinearticles.com/?How-to-Reset-the-Brother-DR250-Drum?&id=6769340

Resetting the DR250 drum without the starter sheet. In the event that the user does not have a starter sheet and is likewise unable to hand cut one, there is still one sequence left to reset the Brother DR250 drum. First, open the printer front cover and press the 'Option“ button while the front door is still open. Next, press the up arrow or the positive key to reset the drum automatically with no starter sheet required. All you have to do is to follow these instructions and a reset could be done seamlessly.