Why wont my epson dx8400 print in black?

Why wont my epson dx8400 print in black? I got an error message saying something about flooded print heads. took my printer to be seviced, print heads cleaned etc. it was checked and I was advised to use epson cartridges at all times, so as instructed installed new inks. ran through proceedures etc but no black ink comming onto the paper. done nozzel checks , print head cleanings and everything but still no black ink on paper. Now to add insult to injury the new cartridges have ran out. Any ideas why I have this problem and how to fix it would be welcome. Or should I get a new printer? Thanks in advance for your help