Zanussi 22ZT907, Service Manual

Page: 16 / 64

417
Power supply p.c.b.
It converts the mains voltage in
DC voltage available at five
outputs with values of:
(two outputs);
These voltages are
stabilized and separated from
the mains.
BS Vertical deflection
This p.c.b. generates a sawtooth
voltage at frame frequency which
is used for driving the vertical
deflection yoke. It supplies a
similar voltage to the
section of the
synchro. separator p.c.b. to
obtain the E/W pincushion
correction.
It supplies a frame frequency
pulse which is used for the
luminance, chrominance and video
amplifier p.c.b. blankings. It
receives the vertical synchro.
from the synchro. separator
p.c.b. and receives from the
chassis a voltage proportional
to the beam current.
BS Synchro. separator and
pincushion correction
p.c.b.
The p.c.b. processes the video
signal. Said process consists in
separating the horizontal
signals from the video composite
signal. The "pincushion
section receives a
sawtooth shaped signal and
converts it into a parabolic
shape for E/W correction.
BS Horizontal deflection
p.c.b.
This p.c.b. amplifies the pulse
sequence at line frequency and
drives a circuit operating as
an ON-OFF switch for supplying
the deflection current to the
horizontal yoke. It also
receives the parabolic signal
which acts on the diodes
modulator for E/W correction.
No adjustments needed.
BS 418 CRT p.c.b.
It includes protection and
matching circuits for the three
signals (red, green and blue)
with relevant voltage
dischargers. In series to each
signal circuit a switch is
provided for black level
adjustment.