How to solve the high temperature of extruder

How to solve the problem of high temperature in some section of extruder  

If the temperature in a certain section of the extruder is high, the main reasons are as follows:  

1. The fan does not work or the fan turns incorrectly:  

2. Temperature control meter or PLC adjustment failure:  

3. The relay or bidirectional thyristor is damaged.  The main solutions are:  

1. Check the fan switch and cable connection:  

2. Check the temperature controller or adjust PLC parameters, or replace the temperature controller or PLC  

3. Replace the relay or bidirectional thyristor.