The black ink started too play up,so I installed a non genuine one.
The print was appalling so I contacted the retailer. After a couple of messages and samples, he said it was a blocked head, not the cartridge. I don't usually agree with sales people, but the more I looked into it, the more it was feasible.
I've removed the printhead a couple of times now, and cleaned the heads. I did see a difference each time, so the blockage idea seems confirmed.
However, it still has blockages.
I used isopropanol and cotton buds. The second time, I soaked it for an hour or so, but it's still blocked.
I looked at getting a new head,,,, until I saw the price.