Service Manual
6-17
Troubleshooting
6
6.
If the problem persist, a “freeze/thaw” cycle may remove the
obstruction. Turn the printer off and allow it to cool for at least 3
hours. Then turn it on again. During the cycle, ink in the nozzles
solidifies and is forced out by expanding ink when the ink is remelted.
Purge three times after a freeze cycle, if necessary.
7.
If the printer is located above 1350 m (4500 feet), use Service Support
menu item High Altitude to select the alternate head drive waveform.
Service-performed procedures to recover faulty jets
1.
Check for proper maintenance station vacuum seal. Check to see that
the printhead is correctly positioned in its home position.
2.
Run a clean head cycle and observe the operation. The maintenance
station gasket should be in full contact with the printhead faceplate
during the purge cycle. Inspect the air hoses.
3.
Following a clean head cycle, move the printhead to the far left end of
the rails (viewed from the front) so you can inspect the printhead
faceplate. It should be clean with no ink droplets adhering to it. If not,
the wiper element may need to be cleaned or replaced or the faceplate
is damaged requiring the printhead to be replaced.
4.
The air hose leading to the top of the maintenance station should be
routed so that it does not pinch or bind with the sheet metal bracket.
(Refer to the Chapter 8 topic, “Maintenance station.”)
5.
Ensure the air pump runs during the cycle, if it doesn't, check its
40 VDC drive voltage. Replace the air pump if the voltage is correct.
Under a running load, the 40 VDC supply measures about 24 volts.
6.
As explained in Chapter 9, “Vacuum check” on page 9-32, measure the
air pump's vacuum to ensure that it is correct.
7.
You should hear a hiss (vacuum break) just before the maintenance
station pulls away from the printhead face. If the hiss is absent, check
to see if the printhead is improperly positioned due to an X-axis
movement problem. Also ensure that the maintenance station gasket
is in good shape. Check that the maintenance station cam pin is
inserted into the groove of the head maintenance cam gear (so the gear
movement pushes the maintenance station against the printhead
faceplate).
8.
Also inspect the maintenance station filter (which protects the air
pump), to see if it is clogged with ink. (If it is clogged, you must
replace it along with the maintenance station and tubing.) You can
pinch the air hoses to feel if they are clogged with ink.
9.
Check the connector connecting the printhead to the carriage board. If
you suspect an electrical connection problem, clean the connector
contacts and re-seat the connector.