5100 error

1. On the operator panel, press and hold the <ON/OFF> button for one second. (The display will go blank.)
   
   Note: It may be necessary to unplug the power cord if pressing the ON/OFF button does not shut off the printer.
   
   
2. Wait approximately ten seconds and then press the <ON/OFF> button again.
   
   
3. Wait until the device has completed its cycling process before submitting another job request.

if this did not check if the cartridges is fitted in place ,even this did not clear the error then
Turn the printer off.
. Take a #10 envelope and feed it through the left side of the manual feed slot until it comes right through the printer to the back of the exit rollers.
. Move it up and down first, and then slowly move it over to the right side. If something is stuck under the black guide plate, this may work it loose.
and then power it on and check ..if this fails it must be serviced ...