4800 nozzle problem

Hi all,

I have a problem and I’m running out of options, so I turn to you hoping you can give me some advice.

I have a 4800 that I have been using for prints and digital negatives with a P6 set with both PK and MK and gloss.

We try to print at least every week and up to a few weeks ago this went fine.
At that point I started to notice that the first ¼ inch and last ¼ inch of a print had some stripes if this part was midtones.
So I did a nozzle check with cleaning and noticed just a few blocks missing at the KCMY side.
I let the head soak on a lint free cloth with piezoflush overnight and did another nozzle check only to see that the problem had gotten worse.

Now there were a lot of blocks missing:

At this point I noticed that the ink in the cartridges was on the low side, so I put in more ink that I still had in cartridges from the 4900 that we used before and is totally dead.
When filling the cartridges I noticed that the cyan didn’t prime. I tried to suck out the air from the outlet, but nothing happened, so I ordered a new cyan cartridge.
The cartridge arrived this week, I transfered the ink and did two power cleanings from the printer maintenance menu.

It got even worse:

I thought that there could be air in the lines, so I just went ahead with an initial fill, to be sure that all lines were filled with ink.

To my big surprise and shock, this messed up everything:

By now the ink in the cartridges is below the minimum line, so I have to order new ink.

I also got cap replacements for the capping station and a spare flushing station, I figured I might as well replace these too.

I also got cleaning syringes that you connect to the head to force ink or cleaning fluid through them.

Before I order new ink and spend more money I would like to get your opinion.

What can be happening? What can be causing this problem?
How can I fix this?
I have seen in a video that you can disconnect the printing head to inspect it visually. Is it a good idea to clean the head manually?

Please help!

have you inspected and cleaned the flush box area? If this is gunked up on a particular side it could be pulling ink but not effectively enough to actually bring back the head.

Because this is happening to OK channels (top right first image). This is not a head issue. It COULD be a damper issue. I suggest dampers replacement as well as cleaning assembly replacement (although you could do a cleaning assembly replacement and then a normal head cleaning (not power) and see if this fixes it before changing the dampers. There’s a good chance the dampers are full of junk because they need to be replaced every 2 yrs. They have filters in them.

Also, I asked this by email, but are your vent holes on the carts open during all of this (+ printing). They should be.