Problem Printer

This is my first post & I'm not a computer technie, so please bare with me. I have an old Dell printer, but it's been very faithful. I got a new color cart. & installed it yesterday. When I went to print, the printer showed a message that the "Left cartridge is incorrect". I never did anything to the Left (black, of course) cart. I have tried everything I could do and at last called Dell Support, but was on hold this a.m. for 30 minutes, so I hung up. I know it must be something simple, but nothing I've tried works. I've tried taking both carts. out & reinstalling, tried the "aligning process", checked the cables, cleaned both of them etc. It may be time to get a new printer, but it's just a coincidence that this happened immediately after I replaced a new cart. One other thing, the black cartridge symbol on the "Print Screen" on the computer shows a Question Mark on it which I've never seen before. I can't find any meaning to that in the Troubleshooting section on Dell's website. I'd appreciate any suggestions you might have. I really need my printer back.  Thank you.