H-3 error code in a Sharp ARC260m

Question

I have a copier with an H-3 code, I've cleaned out the fuser and reset the thermostat, but I can't get the sequence of buttons to get me into the service mode. I worked on older Sharp models but they have a different sequence of buttons to get to service mode. If someone could help me I could get to Sim 14 and see if the fuser is okay. Thanks for any help you could give.