I have error code u4 from copier olivetti 9814 how to fix it

SOURCE: Xerox Copier Machine - Error U4

The fuser is not warming up.
On that machine under the web there is a thermal fuse on a white plastic mount, it has one screw through it.
It is most likely blown. Possibly caused by a jammed paper in the fuser.
That fusable link needs to be replaced.

SOURCE: U4 error code - Xerox 5328 copier

U4-2 Low fuser temp problem U4-3 High fuser temp problem U4-4 High fuser temp problem U4-6 High fuser temp problem

replace thermistor in fuser unit

SOURCE: I have a copier olivetti d-copia 20W, after change

For the Sharp copiers it is #-*-C-*