I have a Brother MFC-J480DW using refillable cartridges for about 5 years with no problems. Today after printing a one page document, the printer quit recognizing the yellow cartridge. Tried re-installing several times with no success. Cleaned the chip contacts and tried again with same result. Did a power reset of machine... problem continues. I am ordering a set of compatible cartridges to try that in case the chip on the yellow cartridge has gone bad. Any suggestions I haven't thought of? Can I get at the contacts inside the machine? I doubt the problem is there as the failure mode happened while printing and not while inserting cartridge following refill.