Ricoh FACSIMILE FAX77 Field Service Manual page 128

Reassemble the machine.
6.
When replacing the thermal head, fit pin
[D] into slot [E] at the front, then fit pin [F]
into slot [G] at the rear.
When replacing plate [B], the pegs on the
plate must fit into the indents on the main
body.
7. Program the pulse width and thermal
head size (Function 97).
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