Tatung V17AFTW, Service Manual

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Refer to circuit diagrams Sheet 6 of PWB-0452.
The signals of panel interface are all from I019 to the LCD Panel.
The signal FPVCC (Pin#96 of I019) and MMTB3904( Q003) control the +5V
power to the LCD Panel.
The signals FPBACK and DVD0( Pin#95
、
62 of I019) are used for the control of
backlight’s On/Off state and Panel luminance.
The signals SHFCLK
、
PDE
、
PVYSNC
、
PHSYNC come from Pin#90~94 of I019,
and then fed into P018. These four signals are used for panel image display
controls.
Pin#A1BLU0~7
、
A1GRN0~7
、
A1RED0~7 and B1BLU0~7
、
B1GRN0~7
、
B1RED0~7 are data output from I019 to P018 and P019( to LCD Panel). They
are buffered by LP01~LP12 and filtered associated capacitors. These outputs are
organized into even and odd connectors, each with 18 bits.
9.2 Keyboard Circuit & IR Lens board
The keyboard and IR lens circuit are shown in chapter 10.2 of the circuit
diagrams.
9.3 Inverter Circuit
The inverter board is fed with +12V through P017#1, #2 on main board and
offers 10.5 mA (typical ) to each lamp of backlight in LCD panel.
The brightness adjusted in OSD menu is to control the voltage at P017#7 while
this voltage is offered by I019(Scaler:TP6760)#62.
The range of the voltage is from 0.5V to 2.8V. If the voltage of I017#7 is 0.5V,
the screen will get light ; if it’s 2.8V, the screen will get dim. It means that the
different voltage will change the lamp current through the inverter to make the
screen lighter or dimmer.