BestCode NExT 82 - Common Printhead Issues

BestCode Next Series 8 Technical Manual October 2022 Page 195 of 290
Clean Start / Stop Issues
The components that directly impact Clean Start / Stop are as follows
1) Ink Pump
2) Ink Filter
3) Venturi
4) Green Tube
5) Black Tube
6) Ink Manifold
7) Pressure Transducer
8) Red Tube
9) Dampener
10) Printhead Valve Manifold
11) Printhead 3 Way Valve
12) Drop Generator
13) Drop Generator Nozzle
14) Blue Tube
15) Tank Solvent Valve
16) Yellow Tube
17) Bleed Valve
With such a long list, we need to wisely choose where to begin.
Diagnostic 1
Perform backflush nozzle up to 10 times then test the Clean Start/Stop functions.
Diagnostic 2
In the Fluidic screen, test that the Pressure Sensor is working correctly. Pressure reading should be
constant and not fluctuation. Bad pressure readings can cause low pressure and bad jet starts.
Diagnostic 3
Test the flow of ink into the drop generator. Run the pump with no valves on. If Ink comes out of
the drop generator, the Printhead 3 way valve is not fully closed and is allowing ink to exit when it
should not. Replace the Printhead 3-way valve.
Diagnostic 4
Test the flow of ink into the drop generator. Low pressure at the drop generator cause cause bad
starts. Remove the Drop Generator nozzle. Run the pump with the printhead valve on. At 15 RPS, a
strong flow of Ink comes out of the drop generator. If the flow is weak, there is an obstruction
between the Pump and the Nozzle. Test the Pump, the Filter, the Venturi, the Green tube, The Ink
Manifold, the Red Tube, the Dampener, the Printhead valve manifold, Printhead valve, and drop
generator for obstructions. Replace the faulty part.
Diagnostic 5
If the flow out of the drop generator is good, remove and clean or replace the nozzle.
Diagnostic 6
Test that Makeup is being pulled through the drop generator. Re-assemble the entire system,
nozzle included. Go to the fluidic screen and run the pump to 40 PSI. Enable the Solvent Tank Valve
and the Bleed valve. If Makeup is not pulled through the Drop Generator, there is a vacuum leak or
an obstruction that is preventing Solvent from entering the Drop Generator and cleaning out the
components during the Clean Start/Stop.
Test, then clean or replace the Bleed Valve and Solvent Tank Valve. Check all tube connections for
the Orange, Blue and Yellow tubes. Make sure the tube is not clogged by testing each tube with a
spray of cleaner.