Hi, Ive had a problem with a Trace Elliot 4x8 Combo cutting out mid gig. In the past, ive had a speaker cone glued, and more recently the heat sink replaced - both by a professional repair person. Since the heat sink (and a couple of caps) were replaced, ive noticed that the amp has been cutting out at gigs after about half an hour. The repair guy i use is on holiday, and i need to try and get this sorted! Ive tried; *Giving it a good hard bang (maaaatron) *Patching the effects loop in the back of the amp *Giving it a good clean out *Different power leads *Different jack leads *Different basses When the sound goes, theres no audible buzzing, crackling, or thump, it just goes. Is there anything ive missed? Please help!