Inkjet Priming and Cleaning

And now, on the Very Secret Life of Machines….

Here’s a look at a very curious mystery on a Brother MFC-J435W. On this printer the ink cartridges are loaded at the front panel and a set of small (silicone?) hoses carry the ink to the print heads.

image

This is what they’re supposed to look like. The printer was brought to my desk after a new set of cartridges were loaded and it only printed black. I didn’t get a photo of it but the ink lines were totally empty…??!!

image
Ink everywhere but not a drop to print

So how do you prime the lines? Well, Brother thought of that. The rubber cap that seals the printhead when not in use is connected to a vacuum pump.

image

The cap and squeegee blade used to wipe the head are visible at the end.

Triggering the clean cycle over and over finally primed the lines and the color output slowly returned.

image

So I’ll answer this mystery: What does an inkjet cleaning cycle do? Well, first off, the printhead periodically moves to an ink toilet off to the side and wastes some ink to keep the ink in the passages fresh. This is audible as a soft high pitched (about 5000 Hz usually) tone.

image
The ink toilet.

Second, a squeegee is moved into the printhead’s path and it’s wiped clean of any dried or accumulated ink. This is typically done during print jobs as well and can be heard as one or more clicks.

Third, during manually initiated cleaning or priming cycles or after installing new cartridges or printheads, the printer uses the big suck to prime the ink feed system.

This vacuum pump isn’t present in all printers. Generally if your printer uses cartridges where the printhead’s changed along with the cartridge, it isn’t present or needed, and if your printer has permanent heads (Epson) or uses tubes like this one, a priming pump is used.

Long ago NeXT made inkjet printers that even had vacuum switches so it could confirm when the ink was primed and fix it if not. Most ain’t that fancy.

So if your printer drops a color, look for these clear tubes – they shouldn’t be!! If the vacuum pump isn’t doing its job, make the printer move its head then cut the power while it’s uncapped. Clean the cap/vacuum with a wet paper towel or cotton swabs. The ink will stain fabric and skin. You were warned. Power back up and see if it’s happier.

Only major gotcha here– repriming the color ink lines consumed a full cartridge!

Oh well– not MY printer…

image
Before cleaning the Big Suck.

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.