ABB AC drive fault

Thanks for the opportunity of this great information exchange. I'm recieving an error F0018 which is Therm Fail. In manual says drive internal fault. Thermistor for drive is open or short circuited. The fan works, good circulation,is there a part to change or a new drive is needed?
The model # of the AC drive is ACS150-03U-04A1-4.

This fault indicates that the thermistor inside the drive(temperature sensitive resistor) is reading a value that is out of the expected tolerance. Generally the resistance indicates to the drive that the drive internal temp is in range, and possibly even control the internal cooling fan. Dont think this is user reparable ... you would have to find it and replace it with the correct thermistor or substitute a resistor whose value satisfies the drive. Not sure but you may be able to disable this monitoring feature in the parameters (not sure exactly which one) but you would have to look in the manual. Should be near the end of the parameter list. Hope this helps .

The drive is toast, unfortunately. This component is not accessible to repair or replace.

the temperature sensor inside the drive is defected , this sensor always is installed on the heat exchange to check the temperature of the drive , i think you can change this sensor