Epson Stylus 1500, Service Manual

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Pump Operation
The pump draws ink from the printhead nozzles and drains it into the waste ink drain tank to
eliminate dust or bubbles in the nozzles. The figure below illustrates pump operation. When the
paper feed drive motor rotates backward (counterclockwise), the color pulleys in the wheel pump
unit rotate in the direction of the arrow while squeezing the ink tube to push the ink out to the
waste ink drain tank. When the motor rotates forward (clockwise), the black pulleys in the wheel
pump unit rotate in the direction of the arrow while squeezing the ink tube to push the ink out to
the waste ink drain tank.
Table 2-6. Pump Mechanism Operation
PF Motor Rotational Direction Operation
Clockwise (CW)
forward rotation
❑
Black ink absorption
❑
Wiper reset
Counterclockwise (CCW)
backward rotation
❑
Color ink absorption
❑
Wiper set
There are two pump rollers in the pump unit, and drive power is supplied from the paper feed
motor via the pump drive gear (D/E gear), which is moved by the carriage. In the pump unit, the
transmission gear supplies both the black and color pulleys, which are each rotated by the
movement of the other.
In k D r a in in g
V a c uu m in g
Pump Motor (CW): Color Pumping
No Ink Draining
No Vacuuming
Pump Motor (CW): Black No Pumping
In k D r a in in g
V a c u u m in g
Pump Motor (CCW): Black Pumping
No Ink Draining
No Va cuuming
Pump Motor (CCW): Color No Pumping
Note: CW = Clockwise; CCW = Count erclockwise
In k Tu b e
Figure 2-15. Pump Operation
Operating Principles
2-14 Rev. A