I have an Epson 4900. As I was shutting down, I removed a cartridge to reorder ink. Now the cartridge will not lock into place when reinserted. I've removed all the other cartidges and replaced them - they are fine. I'm just having a problem with one and obviously don't want to force it. I don't see any signs of damage.
The Light Black and Light Light Black cartridges both are the same color. I had pulled the LLB to reorder, and by mistake picked up a used LB cartridge to be recycled and was trying to insert it instead. Obviously, that does not work.