TOVIS P/N
MTG-1972XN
DATE
2002.03.11
REV NO.
0
TOVIS
Color Monitor Service Manual
PAGE
24/30
8-6. FBT (Fly-back Transformer)
The high voltage for CRT anode focus, G2 voltage for CRT and - 12V for
vertical deflection are generated by the FBT.
Also, -130V for G1 voltage, -12V for the vertical supply voltage are extracted
from the FBT.
8-7 ABL (Automatic Beam Limiting)
The voltage of the FBT pin10 is affected by the anode current of the FBT.
When the voltage at pin 10 is decreased, the anode current is increased
accordingly. When the anode current is increased, contrast is set at the
certain limited level (28FL in white pattern) that is set by inner voltage of
IC401.
8-8. Video amplification section.
8-8.1. Video pre-amplifier (IC401)
Input video signals are amplified by means of IC401, and the amplified
signals drive the video output stage (IC402).
Video gain is adjusted by DC voltage at pin 12 for ABL control.
8-8.2. Video output stage (IC402)
The video output signal from IC401 is amplified again by IC402, and
IC402 apply video signal to each cathode of CRT.
Q405, Q406 and Q407, which is operated by I2C BUS control through
u-com, adjust cutoff voltages.
8-8.3. OSD (On Screen Display: IC403)
The OSD signal is applied from IC403 to IC402.
It is controlled by I
2
C BUS control line.
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