Black ink blobs appearing on prints after switching from MK to PK cartridge in R3000

I switched from my matte black to photo black cartridge and began printing on epson premium luster photo paper when I noticed large black blobs appearing on the print. I’ve attached some photos to illustrate what’s happening. These blobs don’t show up when I run a test print only when I try to print a file from an application like Photoshop or Acrobat. Can anyone guess what might cause this. I’ve run several head-cleaning cycles and several test prints but gaps still remain. The blobs though are killing me!

It looks like you may have a damper switch leak that happens on the R3000 and 3880s.

You will probably need a new ink supply unit. Switch back to MK and print and see if you still see blobs. If not, it’s just the film over the PK damper that is damaged.


Thank you for putting your mind to this so quickly. I did what you suggested and switched back to MK. The print was clean, no blobs! So now my question is: how does one replace the “PK damper.” Is it a part that I can replace myself? Obviously your dealing with someone who know little about the guts of his machine, but I am fairly competent mechanically.

Thanks in advance…

I had the same reservations about replacing the ink supply unit. However,
if you buy ($10) the manual from, print it out as large as
possible (within reason) and in color, studying it very carefully, then you
can pull it off. Buy the part ($183) before you start to work on your
printer; this will prevent you from going down too many rabbit holes before
you even start. You might also consider replacing the ink/cap unit ($55),
which is very straightforward. If you study thoroughly and work slowly,
you’ll be amazed with yourself. BTW, as I removed the screws from the
printer, I put each set, e.g. the back cover, etc., into separate, smallish
manila envelopes and labeled them, the numbered sequence of removal and the
number of screws that I placed in each envelope. Save the envelopes for
later, you never know…

Here are a couple of older threads about this (3800/3880 specifically) that may be helpful:

Thank you for the diagnosis Walker. But I have been unable to locate this part other than purchasing the complete assembly for about $180 from Compass Micro. eBay had nothing that I could find. Do you know of a source?

Sadly, I think you are right. It only comes in complete assembly now.


I am thinking about ditching the (broken) R3000 (that Was turning out large blobs of ink and required a $200 part) and move to a P600 but I have a few questions about whether these two printers can use the same ink? I assume they cannot share the same cartridges right? That would be too easy. Can anyone help with this decision?

They actually can use the same ink. The ICC profile here are built for the same ink.

Technically you can also use the same carts but just switch the chips with these:

but the P600 chips will not reset reliably before ink is used up with these smaller R3000 carts. We are coming out with a new set of larger carts for the P600 which are our own design which keep this problem from happening. The P600 carts available on the market currently are the R3000 style carts which can run out of ink unless you are vigilant in topping them off.

So in short, you could simply by the P600 chips and keep using your current carts in the P600 but you need to top them off regularly (BEFORE RESETS) to keep air from getting into your system. We’ll have the official P600 carts available soon or you can invest in our current solution which is the P600 CISS.