I have a Sony MDSJB940 MD player. It's developed a fault. After about 20 mins or so of playback there is a buzzing/rasping which develops along with the audio. When I press pause the noise dies very quickly and the system falls silent. However when I press play again the noise resumes. The discs I am playing are perfect, so this is either a playback or output fault of the MD player. Has anyone come across this fault on their machine......and if so how would I fix it? Thanks. Jon.