P400 cart gone bad?

Today, I refilled and reset my P400 carts for the umpteenth time. After re-inserting the carts, the printer displayed the ink check light over the magenta cart. I carried out the dummy cartridge / Piezoflush procedure three times. By the third time, the Piezoflush came up clear into the syringe, so I assume there’s no clog in the print head. But the magenta ink check light remained on. I also used the priming tip on the cart, even though I know the you only are only supposed to do this after filling for the first time. But the ink check light remained on. I’m surprised there’s a problem, since I printed as recently as yesterday.

As an experiment, I swapped the magenta cart for a spare magenta cart that I had filled with Piezoflush. The magenta ink check light went out! Does this mean the old magenta cart has failed? Is this normal after 1.5 years of use? Can it be repaired? Or should I just replace it? Fortunately, I have a spare set of empty carts.

The ink check light just means the chip is registering low. There is zero relationship between the liquid level and chip level (no sensor involved). These are ARC chips and are fully described in the manual/instructions: https://shop.inkjetmall.com/small-format-refillable-cartridge-instructions


I know the printer does not sense ink levels. I use an IJM P400 chip resetter.

I swapped in a magenta chip from a new cart and the ink check light went out. So the old chip must be bad, since after resetting, it registered low. Is that right?

The manual only says to replace carts once a year, but it doesn’t say how they might fail if you don’t replace them.

Sorry, I see.

Yes, when these particular chips fail they will be un-resettable. That is their tell.