SONY KV134OUB

There’s been a low level of hum on sound since new, even
with the volume control turned right down. The hum frequency seems to change if the field hold control is set to
make the picture roll. The smoothing appears to be suspect,
but where?
A small amount of residual hum is present in most
receiver designs, and the KV134OUB is no exception. If the
hum level is excessive however the following capacitors are
the ones to check: C231 (220µF, 25V) and C246 (33µF,
25V) on the signals panel, and C607 and C605 (both
4 -7,µF, 160V) on the power supply panel.