We've been using Ninestar - Brother Compatible - NT-P0115-Y. We were looking for high yield because the Brother cartridges were very expensive and became empty too quickly. We just replaced the current yellow cartridge with a new one (same brand) based on your last response and got the same results. We have been using them for a while without any problems. One thing that you should know is that we just moved into a new office. It was working in the new office until we moved it to a different part of the table. Could there be a balance problem?