5518 advanced clear

SOURCE: SHARP AR C250 Digital Color COPIER HAS SERVICE CODE H4 00

Press P-interrupt-C-interrupt and enter test command 14 and Execute to clear your error. Let your machine reboot. If it comes back you have a problem with your fuser. Most likely it's dirt or toner caked on your tempature sensors and they need to be scraped off.

SOURCE: H4 for Sharp Copier AL1551 CS

The H4 code indicates the system did not or is not warming up. It could be a thermostat or thermistor or a board problem or a heating lamp issue.
It requires service.
Check the fuser unit for any debris or excessive build up especially around the thermistors - if you can remove and open up the fuser unit !

SOURCE: Sharp AR-M160 H4 error code

Clearing a trouble code on a AR-M160 is a little different than the AR160.

Try "#" "interrupt" "clear" "interupt" "1" "4" "start key"

This should clear the error. Even if you replace the fusion unit you will need this code to clear the error

SOURCE: I have a sharp copier, model AR-285, H4-01

H4 error pertains to lamp errors.

that would either be the copy lamp or the heater lamp.

check both lamps.

with heater lamps,it's usually caused by either a broken heater lamp or a dirty thermostat on the heater roller assembly.

SOURCE: SHARP AL-1631 DIGITAL COPIER SHOWS ON THE SCREEN CODE H4

Hello sir; You do need following procedure to reset; once begun procedure must enter within four seconds; Press "clear", "exposue mode", "clear", "exposure mode" these 4 keys within 4 seconds, then enter 14, then press start, should take care the problem.