due there a chip in the amp called an operational amplifier under a heat sink on the pcb got the same fault they cost about twenty quid and you will need a soldering iron a screwdriver set remove the chip look at m arkings and maplins or rs components will have a replacement the chip fails when it get top volumed for two long theres regulators with heatsinks so remember three legs wrong sink good luck

i have the same problem . could you tell me if by putting the new chip in it solved the problem, also do you know anyware i could get it done, dont think i,d be good with a soldering iron. thanks