Stereo Receiver Troubleshooting How To Fix A Stereo Receiver?

How to fix a stereo receiver? - stereo receiver troubleshooting

I have two years old Sony tuner / receiver. Often, when I put my stereo speakers or CD player to hear running in the vicinity. When I was a little sign, usually resulting in the CD player or new to give strong performance on all the speakers (I have 5 speakers). What can I do to solve this problem? I recently put all the speaker cable because I thought that the problem was. Of course, this does not help because there is a problem with the recipient. I think that security had probably managed. Thank you!