Electronics in Dusty Environments

I love to listen to music including in my workshop. I have a pair of outdoor speakers power by an older reveiver & listen to FM only. My problem is the receivers keep craping out...I believe due to excess dust. The last 2 receiver lost most of the left channel. My question is, Can these receivers be easily fixed by myself? It would seem the problem would be minor. How would you go about fixing them. My thoughts are to blow the the insides out with air & is there some kind of cleaner to spray? Where would you spray it? Please be specific as I never done this before. Thanks in advance. P.S I've moved the electronics out of thw workshop to avoid dust in the future.