How to enable color ink cartidges in an HP 5940?

[pmcwild]

I have an HP 5940 I purchased about 7or 8 years ago and it worked fine. Recently I purchased a color ink cartridge for it and now, when I installed it, the printer stopped working altogether. It shows the printer to be out of ink when both ink cartridges are installed. When I take out the color cartridge, the black ink works fine.
What do I need to do to correct this problem?

 

[bigkel]

Are the cartridges genuine HP or after market brand

 

[bigkel]

Check that you have removed the plastic tape over the cartridge Print Heads (simple things can be overlooked) then try this link http://h10025.www1.hp.com/ewfrf/wc/document?docname=c00864517&tmp_task=solveCategory&cc=us&dlc=en&lang=en&lc=en&product=3742086 I know its not the same model howen but the princeable is the same, Let me know how you go