You're very welcome RayRay, please let me know your results with the new chips. I apologize for not responding sooner, I was teaching a workshop all day yesterday, so was away from email.
As per our warranty policy (http://shopping.netsuite.com/s.nl/c.362672/it.I/id.180/.f), we fully warranty/guarantee products for up to 30 days upon receipt.
We put a great deal of time and energy researching and testing all different cartridge designs to ensure we have the best available for our customers. When we first started selling the internal bag refillable carts for the 7890/9890 and 7900/9900 a few years ago, we felt it was the overall best solution available, but didn't stop there, and have continued testing new cartridge designs as they become available, because we always want to make sure we have the best products for our customers. We've had great results, and have hundreds of customers happily printing with these bag refillable carts for several years, though occasionally there can be issues (like with anything) such as the mold/fit, seal or chip goes bad.
Information about the "no cart" message upon start up has always been included in the instructions, and is resolved by simply opening and closing the cartridge bay doors. The occasional physical fit issue is more recent, and we added info about this on the Frequently Asked Questions section of this support forum. All chips are sensitive to static shock and can wear out over time. The cartridges themselves are robust and can last the life of your printer, though the chips occasionally need to be replaced. We do have a new cartridge design that we've been testing for several months, and will be releasing soon. We feel this new cartridge design provides a better fit in the printer, though works the same in regards to the "no cartridge" message at start up and need to occasionally replace chips. Unfortunately, there is no perfect solution out there (I have even experienced pressurization and chip issues with brand new Epson cartridges), but we constantly work very hard to research and locate the best option for our customers.
Having said this, our main goal is for our customers to be happily printing, which is why we focus so much on research & development, as well as instructions and support for our products.
Based on my experience with the printer model and carts you're using, I recommend you wedge all 11 carts towards the left as per the attached document, then if you continue having errors with the LC and/or Y carts, replace the chips on those carts, and you should be ready to print.
Please let me know if you have questions, your results after trying my suggestions, or if there's anything else I can help you with.
Best regards~ Dana
Paper wedge 7900-RCS-email.pdf (71.2 KB)