P400 chip question

yeah, your understanding is pretty much correct accept the cartridge status is stored in the chip and not the printer.

Every time there is an operation on the printer that uses ink, the printer sends a specific voltage to the chip to lower the chip’s ink level. When the ink level becomes low enough to warrant a cartridge replacement, the printer pauses in mid-print and sends a kill command to the chip (this will normally make an Epson OEM chip not able to be printed with later). This kill command does not kill the IJM ARC chips but simply resets the chip. In oder for that reset to be activated though the printer needs to see that the cartridge was taken out (loss of connection) so you take the cart out, fill it, and put it back in and the cartridge reads full again.


I have carefully read the refillable cartridge instructions for the P400 printer, but I still don’t have a good mental model of how the printer interacts with the chips on the IJM carts. According to the instructions, the PRINTER decides when a cart is empty (whether or not it is actually empty) and turns on the ink light above that cart. When you replace an “empty” cart with an IJM cart, the chip is reset to full.

Here is a scenario: I have three sets of carts: the OEM carts (which I have not yet removed from my new P400), a set of carts with piezography inks, and a set of carts with piezoFlush. I will remove the OEM carts, and replace them with new IJM carts filled with piezography ink. I assume the carts will initially read as full, although I’m not sure how that happens, since the ink lights weren’t on. Before taking a summer vacation, I will remove the piezography carts and replace them with new IJM carts filled with piezoFlush. Again, I assume the newly-installed carts will read as full. A month later, I’ll swap the piezoFlush carts for the piezography carts. The printer will read the current ink levels on the chips. I can continue swapping until eventually, the printer decides some cart is empty. At this point, I can refill the cart and re-insert it, which resets the chip to full.

I’m asking is if my understanding is correct. For example, there’s no need to pry off chips and replace them, or anything like that (as mentioned in other forum posts). And there’s no chip resetter for the P400 cartridges, so I’ll be refilling as dictated by the printer.

I get it! I also see the advantage of “introducing a full cart when a not-full cart is blinking:” That way, when the kill signal is sent mid-print, you simply pop the cart out and pop it back in again and resume printing. A “quick swap-out” probably means that you’re not going to have time to get out the ink bottle and the syringe and actually refill the cartridge.

It seems like this would be a good routine to follow:

  • You can refill a cart any time it’s convenient, but at the latest when the light blinks.
  • When one or more lights are blinking, watch the printer while it’s printing and be prepared to swap carts out and back in.

This discussion has been very helpful to me.

Thanks for your explanation!

From what you are saying, you can only replace an IJM cart when the printer sends the kill command to the chip; that is, when the printer thinks the cart is empty. Only then can you replace the cart and have the printer reset it to “full”. However does this actually happen in mid-print? That would be a disaster.

From what I read in the P400 manual, the printer has eight lights indicating the status of each cart:

  • A light blinks when the printer thinks a cart is getting critically low (but you can still print)
  • A light goes on steadily when the printer thinks the cart is empty (and you can’t print).

Clearly the second case is only going to happen mid-print and the print will be ruined.

If I refill and replace the P400 cart when a light is blinking, I would assume the printer will reset the chip. Otherwise, ruined prints would be a very common occurrence indeed.

So what I think you are saying is: You need to maintain ink levels in the cartridges so that they match as closely as possible the chip readout. This means only filling a cart when the printer tells you to.

I don’t know if I can fill a cart fast enough to suit the printer. Keeping a second set of cartridges is an option that’s out of my price range right now. This really argues for a chip resetter, but unfortunately one does not exist for the P400.

By the way, I discovered today that the P400 does not give you a blinking light when ink is getting low. The ink light just goes on and then you can’t print. I don’t know where I got that idea. It is not in the manual.

If you don’t refill a cart when you pull it out to reset it because the chip finally reads as empty, then the actual ink level won’t match the chip readout. That is, even less so than normal. So you’d have to keep a close watch on ink levels. I assume this printer is like the R2000, in that every time you pull out a cartridge you get a head clean, whether the cart resets or not, so you’d want to minimise how often this happens. If it were me, I’d refill it at that point. I agree with Walker - as long as you’re reasonably quick there shouldn’t be any impact on the print (not sure whether that applies to DNG).

[There is another option - if you can manage to remove the cover to the cartridge bay, then you can remove six of the eight cartridges when the printer is off, and refill them with the printer being none the wiser. Doesn’t work for GO and Cyan, which is a pity as shade 5 is the ink you use the most, and GO is used at an alarming rate for glossy printing.]

No. No chip resets until it has gotten the kill command from the printer. The kill command only sends after the chip reads critically low.

Tell it to epson. This has been the way these printers work (with Epson carts) since forever unless you want to pre-maturely introduce full carts when a not-full cart is blinking (it starts blinking at about half way empty) and waste ink due to forced head-cleanings between cartridge swaps. The alternative here is get a second set of carts (expensive) or a resetter (also expensive and rare).

Generally speaking a quick swap-out on this printer does not ruin the print.


I don’t have a P400, but I do have an earlier model of the same thing, and my recollection is that you should get some sort warning with any of these desktop. At the very least the Epson printing software should warn you, although if you always print via QTR then you may not see it unless you go looking for it.

You need some way of keeping track of ink levels, and preferably without generating lots of head cleans. With auto-reset chips and no manual resetter you get an never-ending sequence of unsynchronised resets and associated head cleans already, without adding to them. Refilling at reset is the most obvious.

If you’re printing with K7 or P2 then almost certainly you’ll use shade 5 the fastest, and you could just refill all of them when you refill that shade. But then if you’re printing using GO you’ll be refilling that often as well, so perhaps whenever you have to fill and reset either GO or shade 5.

Has anyone tried this Chinese-manufactured P400 Chip resetter for the P400? It’s expensive, but if it works reliably it would really simplify cartridge maintenance (see above discussion). Is it compatible with the IJM chips? If not, are there any plans for an inkjetmall version?

As a new user of the P400 (and a new user of piezography inks), having to wait until the printer tells me a cart is empty (it will happen mid-print), and then having to jump up and quickly refill it, is a frightening prospect. All my ink levels are getting low, so they’re all going to need refilling soon, and they’ll need refilling one after the other in quick succession. A chip resetter would totally solve the problem – if it worked reliably.