Hi all, I purchased a Pioneer 313 all in one system about a month ago and up to now it's been great. However for the last few evenings the unit has begun to make a loud buzzing noise when it's been on for a few hours. It's starting to get very annoying not to mention worrying. My question is: Is this normal??? I've checked all cables etc. and everything is set up and working correctly. But the noise is driving me crazy! Please help! regards Denis.