Dot Missing - Epson Stylus PRO 7500 Service Manual

EPSON Stylus Pro 7500
3.4 Troubleshooting Based on Your Printout
This section describes conceivable print quality problems that may occur with this printer
and the troubleshooting points for those errors.
Table 3-24. Diagnosing trouble based on printout
Description

Dot missing

Uneven printing/poor resolution
Smudged or marred printout on front side
Smudged or marred printout on reverse side
White/black banding
DOT MISSING
If the printer is kept for a long time without being used, the viscosity of the ink on the
nozzle surfaces of the print heads, and in the nozzles themselves, increases, and may cause
skipping of dots during printing. After cleaning, (clean several times), if the printer still
doesn't recover from skipping dots, the following points should be checked.
1. After executing the "Inter-user Transport Mode," set the "Transport Liquid Cartridges
(x 6 cartridges)" in place of ink cartridges and carry out initial filling. (The ink
passages will be completely cleaned by the transport liquid.)
After initial filling with the transport liquid, discharge the transport liquid from the
printer in the "Inter-User Transport Mode." After that, set new ink cartridges and carry
out initial filling, then carry out "Nozzle Check Pattern Printing."
Initial filling causes a large amount of fluid to be discharged into the
waste ink pad, so the "Waste Ink A," "Waste Ink B" and "Cleaner"
counters will show considerable consumption. (approximately 10%).
2. If the operation in "1" fails to bring recovery, check the following points.
a) If trouble occurs in all the ink colors:
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Are the print heads and cap assemblies sealed during ink filling?
Troubleshooting
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If the cap assembly / pump tubes have come off.
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If the gear train between the pump motor and pump unit has been misassembled.
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If the cap assembly has failed. (The tension spring has come off, the cap rubber is
damaged, etc.)
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If the pump unit has failed. (The tubes are crushed, etc.)
Refer to
b) If the trouble occurs with a specific ink color:
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Abnormal connections between the ink cartridge, ink holder, tube, damper, print
head. (Fastening nuts loose, or the O-ring deformed or damaged, causing ink to
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leak, etc. could occur.)
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Print head failure
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Left side (B Head) Black, Cyan, Magenta
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Right Side (C Head) Light Cyan, Light Magenta, Yellow
c) If the trouble still has not been recovered from with the items up to this point,
replace the following electric system related parts and check again.
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Check the connections to the CR cable (FFC long) and if there is any damage to it
or not.
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Check the connections to the head cables (FFC short; x 2), and if there is any
damage to them or not.
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The C299MAIN board.
Troubleshooting Based on Your Printout
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If you replace the C299MAIN board or the print heads, the
connection state of the connection cables (FFC) should be
checked. Particularly in cases where the connector is inserted at
a slant, etc., when the power is turned on, it could cause
destruction of the circuit and the insides of the heads, so
sufficient caution should be exercised.
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During head replacement, care should be taken not to mistake
the B head and C head.
Revision A
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