For anyone else with similar issues but no obvious bulging caps I found it to be R88. Started to suffer with intermittent sound, contact cleaner in the rear select switch and headphone jack seemed to help for a bit but it got worse. Usually worse if on for a while or playing bassy music Expecting to replace caps I opened up and everything seemed relatively ok for the components. You can tell the PCB looks like it gets hot enough from the transformer to discolor and bend the PCB... On very close inspection around the edge of the black smoo, you could see a tiny amount of green/blue corrosion on one leg of R88, this corrosion had gone into the leg making a bad joint. (I assume heat from the unit makes the fault intermittent) It broke away with a tiny bit of pressure. 1/4W 4k7 just about fit in the space if you don't have a 1/8W. The pad was bad and had poor joint on the solder side of the corroded leg making me assume this was an issue from manufacturer. I had to clear the broken corroded leg from the hole,...