Hey Vasilis,
I am the service manager at TeamEPS/Fluid Color, I think I can help you out a bit. The most likely reason for sudden nozzle drop out is air in the printheads. To solve this, you will need to burp the printheads followed by recalibrating the negative pressure.
Your primary and secondary (if equipped) filters need to be changed every 6 months or 10L of ink per color. Make sure these are up to date before proceeding.
To burp the printheads:
1) Close all of the Ink Valves.
2) Record your current Negative Pressure values in Topjet.
3) Change the Negative Pressure values to 2.00 and press Set.
4) Remove Printhead Carriage Cover.
5) Open the Waste Ink Tray Drawer.
6) Locate the appropriate Vent Tube.
7) Open the appropriate Ink Valve.
8) Unscrew the Male Leur Cap and place the tube into the bottle.
9) Purge for 2 secs, then pause for 2 secs.
10) Repeat until there is a steady ink flow without air bubbles.
11)
IMPORTANT: Quickly replace the Male Leur Cap before ink stops flowing not to let air suck back into the Printhead.
12) Close the Ink Valve.
NOTE: Repeat the steps for any additional printheads.
13) Return the Negative Pressure to the original values.
14) Open ALL of the Ink Valves.
15) Replace the Printhead Carriage Cover.
16) Purge and Wipe the printheads.
I would next recalibrate negative pressure as this can change slightly with the seasons:
To set Negative Pressure
1) Lower the Negative Pressure
- Go to Topjet => Set => Control System Configuration => Negative Pressure(kp) (kPa)
- Ricoh Printheads - Begin with the Negative Pressure at 3.0kp (kPa)
- Kyocera Printheads - Begin with the Negative Pressure at 4.0kp (kPa)
2) Purge & Wipe the Printhead
- If ink pools quickly on the Nozzle Plate, raise by 0.10 - 0.20kp (kPa) increments
- If ink seeps slowly on the Nozzle Plate, raise by 0.05 - 0.10kp (kPa) increments
3) Adjust until the nozzle plate remains clean after a Purge and Wipe
NOTE: Too much Negative Pressure is just as bad as Too Low Negative Pressure
To check Negative Pressure
• Begin With a Clean Nozzle Plate
• Quickly Press the Purge Button for 0.50 seconds
• A very small amount of Ink will jet from Nozzles
• 95% of ink from all Printheads should draw back up into the Nozzles within 10 - 20 seconds.
• If MORE than 20 seconds, INCREASE Negative Pressure in 0.05kp (kPa) increments
• If LESS than 10 seconds, REDUCE Negative Pressure in 0.05kp (kPa) increments
As far as flushing the printheads, this is a safe procedure, especially on a Gen5:
1) Close Ink Valves.
2) Shut down the printer by pushing the emergency stop button.
3) Disconnect the Ink Tubing from the bottom of the Secondary Filter and replace it with a Male Leur Cap.
4) Attach a piece of Ink Line Tubing with a Male Leur Fitting to a Syringe.
5) Fill the Syringe full of Flush.
6) Attach a Secondary Filter to the Male Leur Fitting end of the Ink Tubing connected to the Syringe.
7) Connect the Syringe to the Ink Tubing supplying the Printhead.
8) Uncap the Vent Tube and place it into a bottle/container.
9) Push two full Syringes of Flush through the Printhead.
NOTE: The Flush will flow from the Syringe, through the Printhead, and out the Vent Tube into a bottle/container.
10) Cap the Vent Tube.
11) Detach the Ink Line and Syringe from the Secondary Filter.
12) Fill the Syringe with Flush.
13) Attach the Syringe to the Secondary Filter connected to the Ink Supply Tubing.
14) SLOWLY push one full Syringe of Flush through the Printhead.
15) Remove the Secondary Filter, Ink Tubing, and Syringe from the Ink Supply Line.
16) Remove the Male Leur Cap and connect the Ink Supply Line to the bottom of the Secondary Filter.
17) Start the Printer by pushing the Power On button.
18) Open Ink Valves.
19) Burp Remaining Air from the Printhead.
20) Purge and Wipe the Printheads.
