Hi, my Goldstar OS-7020 refused to show something on the screen. As far as I can tell, without a schematic, the High voltage is missing. The heater voltage is present as are various power supply voltages (+/- 12V for the opamps and +5V for others. A service manual or schematic could be very andy to trouble shoot the scope. Anybody who can point me to a link or make a copy? Many thanks in advance. Cheers, Marco