How Can We Help?
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.