Yamaha R-300 sound cuts out
I have a Yamaha R-300 receiver and I've been noticing that, when in stereo mode, my left speaker cuts out. It doesn't happen immediately but after about 10 minutes or so after turning it on and playing music the sound from the left speaker kind of crackles and then fades away. And it doesn't cut out when in mono. I tried switching the speaker wires around to see if the problem was with them and not the receiver, but when the sound cut out it was with the speaker connected to the left side. Any ideas on what the problem might be and ways to fix it?
All help is appreciated. Thanks.