Hi. This oscilloscope failed many years ago - I managed to get a new HT transformer and voltage tripler, but on re-visiting it today - found that the oscillator transistor Q458 had
shorted (B-E) and took the 51 ohm resistor out with a bang when I fired it up. So the recommended transistor is a TIP50 (NPN) - replaced that, but nothing happens. All
supply voltages seem to be correct. HT transformer seems OK - (resistances same as the new one, and I'm loath to take it out). Any ideas? Thanks.
