Ricoh C211 Service Manual page 609

11. Adjusting
Ink Detection
CH1 (Standard Signal)
I I
I
4P see ~0"5~ 'ec
CH2
(Detection
Signal)
I
I
[A]
VR901
<
(3
TP1
TP2
b
'%)
Oil-type
~ .
' ' 0
TP-12V
%)
Purpose :
To ensure correct detection of a no ink condition when all the ink
consumed.
Method : 1.
2.
3.
4.
5.
6.
Remove the rear cover of the machine.
has been
Position SW901 [A] on the ink detecting board to the oil type (upper)
position. This switch must always remain in the upper position when using
Ricoh Priport type ink.
Connect the CHI probe of an oscilloscope to TPI, the CH2 probe to TP2
and the GND lead to TP-I 2V. Select the 5 microsecond range.
Install a drum with no ink or remove the ink bottle and make prints until
the Add Ink is indicated (the ink detecting pin is not in contact with the
ink) and turn on the power switch.
Make sure that the wave form is as follows in the no ink condition.
* This adjustment should be made under normal conditions (20%/65?40
RH).
Note: The period of the wave form varies inversely with temperature.
(High temp. -+
period )
If incorrect, adjust the ON
the ink detecting board.
reduced
timing 01
period,
Low temp. + increased
the detection signal using VR901 on
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