fatal:Heater/sensor error - M999

David_0206

The heater is not heating and the following message showed:

Error:Temp. raised to slow. Rise = -0.31 after 13079 ms

fatal:Heater/sensor error - Printer stopped and heaters disabled due to this error. Fix error and restart with M999.

However, we've checked the pin is correctly connected according to the file 'configuration.h'
We use the ramp1.4 and arduino mega2560 board, Version 1.1.0, RepetierHost Mac

btw, we've actually successfully print something few days ago

Repetier

This can also happen if your extruder was hot and in progress of cooling when you started reheating. In that case your decouple timing is simply not perfectly set for your extruder. You would need to increase the timeout to prevent this.

David_0206

Repetier said:

This can also happen if your extruder was hot and in progress of cooling when you started reheating. In that case your decouple timing is simply not perfectly set for your extruder. You would need to increase the timeout to prevent this.

Actually the repetier showed that the extruder was at roughly room temperature and the temperature was still decreasing before the error came out

Repetier

In that case you should check if the heater gets any voltage at all when firmware says heating 100%. Did you do any other changes like firmware update? If not and it worked before the heater or mosfet for output might be defect.

David_0206

the problem came out after we do an arduino firmware update.

Repetier

Guessed that. Check if you changed heater pins compared to old version or used same pin e.g. for fan. Especially for ramps the fan pin is same as second extruder heater pin so it can disable heating when you enable fan for that output.