Random Nozzles - Epson Stylus Pro 4000 Field Repair Manual

Stylus Pro 4000 Field Repair Guide
Note: Random Nozzles refers to Nozzles that fire when they are not commanded to.
Random Nozzle firing is caused by 1 of 4 components
•Head Cables
•Print Head
•Main Board
•Power Supply
Head Cable
Inspect the Head Cables for worn insulation. Place tape over the worn area or replace the Cable.
Print Head or Main Board
If the random Nozzle firing is caused by serial communication problems between the Main Board and the Print
Head, the frequency of the random Nozzle firing changes when the printing resolution is changed. If changing the
printing resolution affects the random Nozzle firing, change the Main Board and the Print Head. Change them one
at a time in any order. Test between each change.
Power Supply
Sometimes (very rare) a noisy Power Supply causes random Nozzle firing.

Random Nozzles

Random Nozzles
Printer Component, Software Item, LCD Display, Printer Button
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