how do I find a fuser for a Xerox XC1040 / Canon PC795 shutsdown and jams?

My copier, hit a power surge it blinks ( H4) , I have tried unplugging it to reset it, ( NOTHING ) NOT A ONE BUTTON will reset. How do I reset this machine.

The other machine , Canon PC 795 shuts down after seven to tem mintues, The paper will not go through .
I have tried cleaning the rollers and all other things I can think of still it will not work right , ( what could be fault to that .