Instruct: Classify Amazon reviews into positive or negative sentiment
Query: a word of caution

I bought this receiver 2 years ago and have been generally very happy with it. Unfortunatly, about 2 weeks ago it started producing a buzz/ distorted playback. I have taken very good care of it so I was quite suprised to have a problem after only 2 years. I tried all kinds of remedies and nothing fixed the problem. The manual and Yamaha tech support were unhelpful as well. Now it looks like I'm back in the market for a receiver when I should have been set for years.