We recommend that you will call us at 805-466-8636 for assistance before trying those instructions .
In most cases (99.9999%) there is a glitch in the circuit board that shut the copier off and prompt this H4 (H 4) code.
To reset the H-4 on models from the workcenter 1200 XD 100 125 130 150 series follow those steps:
Turn copier on.
Press the clear key (orange "C") twice, and the Auto key (most left lower key) one after the other again and again until the display goes blank.
If the display stays on try to change the speed between the clear-auto faster or slower.
Enter the number 14 with the arrows under the display.
Press the print key (the big start green - copy key).
The machine will turn on, warm up and go to ready.