Hey all,
I have an old Japanese oscilloscope, that probably nobody has heard of. It is a Hi-Tech Model O-602. However, I know the cause of its malfunction, that may be could help in the diagnosis. I was in a group testing an electric fence, which probably you know should have voltages in the range of 6000-15,000 volts. A voltage divider was used initially to pick up a signal, even using the highest sensitivity. Since none was found, it was decided to take the signal without the voltage divider. A voltage signal with an amplitude of 4 volts was found. Suddenly and because probably someone moved any of the wires, a high voltage came in. The trace on channel 1, that was on use, vanished, although the CRT display looked normal. Later on, the trace on channel 2 was tested under controlled conditions. It came out for about 10 seconds and then it also disappeared. there is no doubt that something was burned out. If anyone has any idea what could be the most probable element, I do appreciate your advise.