Ink Detection Adjustment - Ricoh PRIPORT VT 2000 Series Service Manual

28 February '91

9.13 INK DETECTION ADJUSTMENT

CH1
(Standard Signal)
CH2
(Detection Signal)
Purpose: To ensure correct detection of a no ink condition when all the ink
has been consumed.
1. Remove the rear cover of the machine.
2. Position SW901 [A] on the ink detecting board to the oil type (upper)
position.
3. Connect the CH1 probe of an oscilloscope to TP1, the CH2 probe to TP2
and the GND lead to TP-12V. Select the 5 microsecond range.
4. Install a drum with no ink or remove the ink cartridge and make prints
until the Add Ink is displayed (the ink detecting pin is not in contact with
the ink).
5. Make sure that the waveform is as shown above when the ink detecting
pin is not in contact with the ink.
This adjustment should be made under normal conditions (20°C/65%
•
RH).
NOTE: The period of the waveform varies inversely with temperature.
(High temp.
6. If incorrect, adjust the ON timing of the detection signal using VR901 [B]
on the ink detecting board.
+0.5
4 µsec µsec
0
reduced period. Low temp.
→
5-72
TP2
[A]
increased period )
→
VR901
[B ]
TP1
TP--12