968 printer not recognizing color print cartridge

Before we start I read all the posts about this - I tried everything that was suggested and I BUY ALL MY CARTRIDGES DIRECT FROM DELL.

So what is the problem.  I happened to have 2 new cartridges (color) and neither one of them is being recognized.  

The printer worked great up until just a little bit ago and I've had it for 4 years.   Now I do have a wireless system but have had wireless from the git go and never any problems like this. 

What is the lifetime of a printer?   I don't use this for work just some printing, copying and faxing as a home office and will really miss it.

Any suggestions?

Jane Q