Vision 708 mixer amp

Question

I HAVE A STUDIOMASTER VISION 708 MIXER AMPWHEN I TURN IT ON ITS OK FOR A FEW MINSBUT THEN THE RIGHT CHANNEL GO'S OFF.IT FADES AWAY. AND IF I TURN UP THE VOLUME IT SLOWLY COMES BACK ON. BUT WHEN ITS BEEN ON FOR BIT IT SPLUTTERS LIKE A BAD CONNECTION. I HAVE CLEANED ALL FADERS & CANT FIND A FAULT IN ANY FADER OR POT THAT MAY CAUSE THE PROBLEM.WHEN THE RIGHT CHANNEL IS OF. THE METRES LEFT & RIGHT ARE STILL FLASHING. SO I PRESUME ITS NOTHING TO DO WITH THE INPUT. INSIDE THE AMP THERE ARE TWO LED'S THEY ARE MARKED..LEFT FAULT & RIGHT FAULT.. THESE ARE NOT LITIT HAS A ON BOARD COMPUTER THAT GIVES HELP. I DONT KNOW IF IT DISPLAYS FAULTS IF THERE IS ONE..IT IS NOT DISPLAYING ANY FAULT.PLEASE ANY IDEA WHAT MAY BE GIVING ME THIS FAULTYOURS JIMBO [e-mail]