technics stereo amp sa-eh790?

[tgbdb44]

i have a technics system sh-eh790 had no problems with it in 10 years of owning it well looked after all of a sudden yesterday when you turn the volume up the amp cuts the sound out power is still going to the system but no sound have to switch of completely and turn back on again as long as i dont turn it up its fine but the minute its turned up loose sound again whats going on is it an overheat issue need some advice if anyone can help