My HP CP 1518ni printer's alert says front door open but its not... is this a sensor problem.?

Hi there! You can easy check if the front door sensor is broken.Open the front door at look for a little hole in the right or left.In that hole you should see little metal lever.Take something thin and long and carefully push that lever.It should make a "click" sound.If the printer detects that the lever has been pushed down the message should go away.In that case the plastic that is located on the front door is broken and can`t push down the metal lever.Even after pushing down the lever the message is there,you need to open the printer and check if the sensor is working fine.If the sensor is working,then you have problem with your DC board and you need to replace it, which will cost you allot of money and time:D.So please replay if you have any other questions about something.Thank you for using Fixya.com!!!