I've had an issue with changing from Epson OEM carts to your refillable carts on my 7880. This is partly FYI but also a request for help.
Four of eight carts have been changed over the past few months as the OEMs ran out, without incident. When I attempted to change the fifth (it was the Light Cyan), I got a 'Cartridge Error' message. I went through all of your support info, checked and eliminated variables as far as possible, but with no success.
The sequence was:
Filled and primed the new cart as usual.
Used the chip resetter to reset chip on the new cart. (I've since learned that you supply carts with chips already reset.)
Installed it in the printer; got 'Cartidge Error'. NB: This was different from the 'No Cartridge' message I got later.
Removed new cart, and replaced the empty OEM cart. Got the 'No Cartridge' message.
Replaced the chip on the new cart with the one that was on the empty OEM cart.
Attempted to reset the old chip, but got no LED on the resetter.
Reset the resetter, and reset the old chip on the new cart.
Reinserted the new cart, but still got 'No Cartridge' message.
Reseated the cart with base to the left, but still got 'No Cartridge' message.
Went and bought a new OEM LC cart.
Installed it, and the printer accepted it OK.
This got me out of trouble, and allowed me to meet a printing deadline, but it doesn't solve the longer term issue: when that new OEM cart runs out, I'm going to want to replace it with your refillable cart, and as far as I can tell, I'm going to have the same problem.
I initially thought that the problem might be with the sensor pins in the printer not making proper contact, either because of dirt or damage. But success with using a brand new OEM cart suggests that this is not the case. I'm now thinking that the sensor is not making proper contact because of the alignment of the chip when using your cart. It seems strange that this should happen on the fifth cart, but I'm guessing that the sensor position has a small tolerance of error for position, and that your carts also have a small tolerance of error, and that the two small positional errors have added up to one that's large enough for a failure. Do you think this is possible?
I notice on close examination of your carts that the top and bottom faces (with the cart in its operating orientation) are not parallel; the vertical face with the label is slightly bigger than the opposite face. This makes your cart higher on one side than an OEM cart - and also means that it sits slightly out of vertical. I saw your advice about shifting the base of a cart to the left to maximise chip contact, and this corresponds to the slight leftwards lean that your carts must have as a result of their shape.
The help I'd like, please, is for you to supply me with a new empty LC cart, so I can see if the printer will accept it, and if not, experiment with shaving the edge/s to make it square in profile, and sit more truly in my printer.
I'd also like a set of new chips for insurance, and a second chip resetter as a backup; I'm not convinced that mine is not shorting out every time I try to use it. I'm happy to pay for these items.
Oh, and I believe that the set of O-rings for the air inlet valve was missing from the kit that I bought last year to begin the changeover process. I assume they should have been in the bag with the syringes, gloves, and funnels? I'd appreciate a set of those, too, also for insurance.
Thanks for your time, and I'll look forward to your response.