I have an International Analogue board for the Classic II that I have had a lot of trouble-shooting problems with. I had noticed a spark around the switch when it is turned on. To get a good look at the area, I had to remove the steel chassis that wraps around the Analogue board. There was sum burn marks on the PCB near RP2 which is a 20 ohm (cold) NTC thermistor. The thermistor has a hole that goes straight through it and the spark seems to occur between the thermistor hole and one of the connectors at the back of the switch. I don't know if this is affecting the performance of the analogue board as the thermistor still measures 20 ohms of resistance but I'll chase the component down and replace it. Anyone else had experience with problems with this component ?
