PHILIPS 320 SERIES

Sometimes when the set is switched on there is a white
raster with black specs on the screen instead of a picture,
and a loud rushing noise on the sound. By rotating the
channel selector to another channel, usually BBC -2, then
back again normal results are obtained. Also a slight
background noise occurs, with a small drop in the volume
level, after about twenty minutes. This can be cleared by
rotating the selector to another channel and back again or
by moving the fine tuner slightly – it may be necessary to
do this several times before the set settles down.
In some sets the tuning range control R2114 is changed
to a 1.5E2 fixed resistor, with a 27kS2 resistor (R2115)
added in series with the tuning voltage feed to the tuner, i.e.
between pin 4 of plug B and the junction of C2104/pin F of
the tuner. See that this is so in your tuner, and set the h.t.
rail to 158V. If the trouble continues, check the 22U2
resistor R2111 from HT1 to the tuning voltage circuit and
the TAA550 regulator. If these items are in order, replace
the tuner.