Have you tried soaking the head?
I'd recommend having a tech replace it. If you have A LOT of downtime you could give it a shot, and have it serviced if you can't get it quite right, but you're better off paying and getting back to running quality prints.
http://www.nationalparts.com/product.aspx?ProductID=47655
$100 per print head!
Mine uses 2 heads 3/c per head. I dont know what yours uses. Is it a 6 color or a 4 color printer?