Recently, I was dissatisfied with the convergence on my set so I started looking for the service menu code to see if I could fine tune it more than the default convergence settings allowed in the regular menu.
I kept looking until I found this site. I though it had some pretty good info "many codes for many brands". It was exactly what I was looking for. Check it out:
EDIT: Umm, be careful with these settings if you don't know what you're doing. When you enter the service menu, be sure to write down settings, before you change them, "just in case".