My ricoh sp c811dn suddenly started displaying the

Here is a way to reset but make sure you follow the instructions correctly.
turn off machine
press online and escape buttons together whilst turning on machine,
when display comes up wait till three options are listed, use arrow button down to select engine, use arrow right to select mode(5.mode) and ok, left arrow to 5.810 SC RESET. OK. PRESS OK AGAIN AND THEN EXECUTE AT BOTTOM OF SCREEN.
Turn off printer and wait ten secs then turn back on.
If only temp error this should reset and start up again, Good luck

552...... A Heating roller warm-up error 2
?? The heating roller temperature does not reach the ready
temperature for 90 seconds after the heating lamp on.
?? The heating roller temperature does not reach 80°C for 13 seconds
after the IH inverter on.
?? Defective thermistor
?? Defective IH inverter
Related SC code: SC 542
1. Check if the heating roller thermistor.

............................................................................
This code is there to prtect against high temp in the fuser that could cause a fire...best to have a tech look at it