My laser printer gives message open heat error how can I fix

This is most commonly caused by a failure of the Fuser unit.
However, in rare circumstances, this can be caused by the Fuser Control section of the SMPS, or the fuser temperature monitoring circuit on the Main Board.
There is a closed control loop:
1. AC voltage is supplied to the Heat Lamp in the Fuser from the Fuser Control section of the SMPS
2. The temperature of the fuser heat is monitored by a thermistor (mounted on the Fuser) connected to the Main Board.
3. The Main Board determines if the fuser temp is too low, correct, or too high and signals the Fuser Control to increase, maintain, or decrease the AC voltage to the Fuser
sorry io say but you had to replace the fuser
call dell costumer support and tell your model no. ask for fuser replacement and they will do it .
Hope your printer is in guarantee period otherwise you had to pay.
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