hi
U need to understand how the ink flows works in all these piezo printers.
There are 2 ways ink can go through the printhead
1- cleaning while the printhead is seating on the capping station
2- printing on media
In first case, with a pump or a syringe connected to the pump output tubes (in case there are 2 tubes, it must be connected with an Y fitting to BOTH tubes, or u will just pickup air from the non connected tube instead of ink from the system). NEVER suck too hard with a syringe... Just as little as u see ink moving on the tubes, or you will delaminate the printhead or break its internal membranes.
This is how it works:
- Printhead seats on the capping station. A mechanic system and a spring, connects the capping to the printheads, and the rubber seals against the printhead. If that rubber is not perfect, it will enter air, and u wont clean or get any ink from the system. This is common failure and usually they dont last more than 1-2 years without problems, doing good maintenance of it (Cleaning the pad softly everyday or 2 days).
- When pump or syringe sucks (inverse pressure), the ink should begin to flow from the cartdridge/bottle/bag to the printhead. When u have ink in your syringe and the dampers are full/medium of ink, and ink never returns... then the system is ok. Only some things can prevent to not being able to print:
a) printhead manifold break (and air entering the printhead). This is a very common failure. The little plastic spikes from the printhead manifold (where u connect the dampers) get little broken and u can replace the manifold or the complete printhead if u dont find a manifold dealer
b) rubber pad inside the printhead is defective. The rubber pad connects the printer manifold to the printhead holes. Usually happens after some years (4-5 years), 4000-5000 m2 or after using isopropyl or other solvents for cleaning the printhead. Please guys... use the correct printhead cleaning liquid ALWAYS. This failure is not so common, but happens. And there is not spare parts so u have to use the rubber from a donnor printhead or replace the printhead. When this defect happens... usually the printhead prints very little, and then stop printing anything. Also if u leave the printhead on the media, ink will appear on the media (will drop in the media just doing nothing). But ink wont return to the cartdridge.
c) electrical problem (mainboard, crboard or printhead board)... usually NOTHING is printed and u have to check fuses and lots of things
well... we return to the first point...
- You should see ink going from the cartdridge to the tubes... if nothing happens, then there is a MAJOR breach (lot of air entering in any part of the system)
- If some ink goes into the tubes, but after stop sucking without the syringe you see that ink returns, there is a MINOR air entering in the system.
- Think that dampers have 2 functionalities... being a small filter for big particles, and more important, act as a antireturn valve...
- If ink tubes loose their ink, is because something from the dampers to the cartdrige is bad
a) cartdridge rubber (usually happens when u move the cartdridge, the rubber is old... more than 1.5 years, or you usually mess with cartdridge). You can replace the rubber with other rubber from a donnor cartdridge, is very easy
b) every PTFE tubing connection... from the cartdridge needle to the damper. The best way to assure is to disconnect every connection, drop a drop of ink in the connection, connect it again, and let it stabilize during 48h before trying the printer again.
c) dampers input (tubing and orings... that little rubber circles), or damper output (rubber seal too big... usually happens aften some years). Always replace the dampers with original ones. I know, they are much more expensive, but the rubbers are good... not like that aftermarket **** that lots of vendors sells. An original damper will last u, at least, years. An aftermarket one can fail in seconds, believe me.
...and we go to second point... printing:
2- The process is similar... when u print, the printhead gets some pL of ink from its internal pool (a very little membrane full of ink). When a noozle drops ink, the negative pressure make it get a little more ink from the damper. And when the noozle is not printing, the damper antireturn feature prevents that ink from the printhead returns to the cartdridge, so makes that printhead always have the same ink.
About your questions... is very difficult to see leakage on manifold. When the manifold is not ok, the spikes are a little soft (not like a new one), and the spikes can move a little (while new ones are really hard). Keep in mind that manifold has another ink microfilter inside, so dont mess with it. Dont try to put needles or something inside, or alcohol or other solvents. You wont see ANY leakage ink from a breach there since negative pressure from the printhead... but air will be taken in that breach.
About the rubber inside the printhead... yes, u can visually see if its ok or bad. The rubber should perfect aligned to the printhead holes and to the manifold holes. If is not fitting perfectly, air will enter. When the rubber is old or bad solvents/inks have been used, this rubber streches and the holes are not aligned anymore. That is the typical problem with aftermarket inks/cleaning liquids. You see they work during sometimes, but finally they destroy the rubber and then the printhead. Printheads are VERY resistant agains solvents and bad inks... but the rubber is not. Is very sensitive, specially to alcohols or acetone.
Note: opening the printhead to examine the rubber should THE LAST thing you should do. First try to suck with syringe from the pump, get ink on the syringe, feel the force... and let it there during some minutes without touching the syringe. Then try to suck a little more. You should realize that u need force and nothing of air entering the syringe. Is difficult to explain with my english hahaha
About replacing cleaning station... I usually repair mines some times before i replace the completely. But is a pain in the *** for new users, so I suggest the easiest, FASTEST and cheapest way (cheapest because time to repair is more expensive than an original station that will last some years perfectly). Is normal to completely replace them every 2+ years, altough I suggest every 12-18 months. Yes you will waste some money, but u will save ink on cleanings and headaches.
