Marantz 2220 Right Channel Static

[givinguptheghost]

Okay, so I apologize if there is a previous posting dealing with this topic; but I searched the forum and couldn't find a similar thread. I am a complete and utter novice when it comes to dealing with my Marantz 2220 receiver, so any help would be greatly appreciated. I love this receiver, but the problem I am having is that after about 10 minutes of use one can hear an over abundance of static coming only from the right channel. I tried just using headphones, but the noise is noticeable there as well. It's quite distracting when I listen to anything, and I am becoming quite frustrated as I have taken it to a stereo shop in town to have it cleaned and the problem still persists. Any help would be greatly appreciated as I'm sure that most people who read this will more than likely know more about these things than I could ever dream.