Troubleshooting Based On Printed Result - Epson Stylus Pro 7400 Service Manual

EPSON Stylus Pro 7400/7800/9400/9800

3.3 Troubleshooting based on Printed Result

This section describes the major print quality troubles and provides troubleshooting
procedure for each of the trouble.
Table 3-4. Print Quality Troubles
Item Description
1 Dot missing
2 Inconsistencies in density, blurring, or unexpected
colors
3 Smudges on the printed side
4 Smudges on the backs of pages
5 Horizontal white or black streaks
6 Vertical bands
7 Intrusion of air into the Ink Tube
DOT MISSING
The printer has a function to detect dot missing by the Ink-mark Sensor and run a
cleaning automatically, however, if the function is set to disabled or the printer is not
used over a long period of time, the nozzles may not fire ink causing severe dot missing
symptom due to increased ink viscosity on the nozzle surfaces and inside the nozzles.
Follow the procedure below to repair it.
Run a printhead cleaning or perform an initial ink charging operation.
1. Run a power cleaning. If the printer does not return to normal by this, run a
cleaning or perform the initial ink charge operation.
Cleaning
Power cleaning Panel setting menu or Maintenance menu:
Adjustment Program: CL4
Cleaning Maintenance mode: SSCL
Adjustment Program: SSCL
Initial Ink Charging Adjustment Program: Initial Ink Charge
Troubleshooting
Reference Pages
p.203
p.204
p.204
p.205
p.205
p.206
p.206
How to Run the Cleaning
POWER CLEANING
Troubleshooting based on Printed Result
2. Printing Nozzle Check Pattern (Test Print Menu) (p.72)
Print a nozzle check pattern. (Panel Setting → TEST PRINT → NOZZLE
CHECK)
Before performing the initial ink charge, be sure to check the
C H E C K
P O I N T
available space of the Maintenance Tank by its counter as a
large amount of ink will be discharged to the tank for the initial
ink charge. Have an another Maintenance Tank as a
replacement if necessary.
Also check the remaining amount of ink before the initial ink
charging. If the remaining amount is lower than 50%, replace
the ink cartridge with a new one to perform the initial ink
charge.
If the dot missing still occurs after running the power cleaning, check the
following items.
When the dot missing appears in all colors.
• Check if the printhead and the Cap Assy. are kept in absolute contact with
one another during ink charging operation.
• Check if the Cap Assy./Pump tubes are disconnected.
• Check if the Cleaning Unit has reached its end of life.
Check the Cap Assy. for any damage such as damage of the cap rubber.
•
• Check the Pump Unit for any damage such as crushing of the tubes.
• Check if the printhead is defective.
Check if the fuse on the Main Board is blown.
•
• Check that the Head FFC connector is securely connected.
When the dot missing appears in particular colors.
• Check the Head Cleaner for any dirt.
• Check the junctions of the ink cartridges, Ink Holder, tubes, dampers, and
the printhead for any abnormality.
(Ink may be leaking by loosened fixing nuts, deformed or damaged O-ring.)
• Check if the printhead is defective.
Perform the power cleaning again.
•
If the trouble still occurs even after performing all the troubleshooting described
above, replace the parts listed below and check if it returns the printer to normal.
PRINT HEAD (p.267)
•
• BOARD ASSY., MAIN (p.232)
Revision B
203