Ricoh C211 Service Manual page 632

3. Drum Section Trouble
< Phenomenon>
3-2. No add ink indication D + & with low image density. Ink may not be supplied when
a low ink condition occurs.
D+~
e Possible causes>
1. The variable resistor for ink supply
detection is not adjusted correctly.
2. The ink detection board is faulty.
1).
2).
a.
b.
c.
Check the wave form using
cilloscope.
an os-
When there is no oscilloscope.
Remove the ink from inside the drum.
Turn VR 901 on the ink detection
board fully clockwise or counter-
clockwise.
If LED 102 on the main PCB does not
go out, the ink detection board is
faulty.
e Countermeasure>
1. Adjust VR 901 on the ink detection
board until the wave form of TPI and
TP2 on the ink detection board is as
shown below.
NOTE:
Before adjustment, remove the ink
from inside the drum as much as pos-
sible.
2. Replace the ink detection board. After
replacement, adjust VR 901 as ex-
plained above.
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