Please try the following.
Turn on the printer and open the door where the toner cartridges are located.
Press the 1 key on the keypad and it should bring up a toner reset menu that will allow you to reset on the toner.
On the screen, select K.TNR STD to reset the Black. Hopefully this will work for you. Let me know if you have any trouble. Thank you.
Try this method and see if it will allow you to reach the toner reset menu instead.
1- Turn on printer 2- Open front door to access toners 3- Hit the "Start" button for the Black and White copies on the right side of control panel 4- Quickly type in the number "10" on the numerical keypad (1 then 0, quickly in succession)
5- Then try to reset the black toner.
Sorry for the slow response, let me know if this does not help.