The trouble with this set is no sound or vision. On checking
it was discovered that the chopper device Q603 is shortcircuit, whilst the resistors in series with it (R607/R610)
both overheat – R607 subsequently went open -circuit. Is
the SG6533 a suitable replacement for the chopper?
The SG6533 can be used to replace the SG608 (early
production) or SG613 (later production) chopper – it’s a
gate -controlled switch incidentally. The reason for Q603 going short-circuit is almost certainly that the line output
device Q510 – another SGS, of the same type – or the
flyback tuning capacitor C542 (0.018µF, 1.5kV) has gone
short-circuit. Replace as necessary, along with the damaged
components on the power supply panel.