Ricoh PRIPORT VT 2000 Series Service Manual page 143

28 February '91
7.9 DRUM MASTER DETECTION: VT2300/VT2500
[A]
[B]
[C]
[B]
The drum master detection sensor [A] mounted on the drum rail detects
whether the master is on the drum.
When there is a master on the drum, the black seal [B] is covered and the
sensor detects the light reflected from the master [C]. Printing starts when
the Print Start key is pressed.
When there is no master on the drum, the black seal is exposed. The black
seal does not reflect light back to the sensor. The "M" indicator blinks and
printing does not start when the Print Start key is pressed. The Master Mak-
ing key can only be pressed after an original is set on the original table.
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