Xav-7W - Display; Xav-7W - Backlight Operation - Sony XM-1502SX Training Manual

Angle – From the monitor open position, the motor can be rotated in small steps to change viewing angles.
IC703 accomplishes this using feedback from a PH780 photo detector to detect the fine movement of the
gears (CN15/pin 15). See Figure 3-9.
When either + angle button is pressed, IC703 changes the logic voltages (CN15/pin 13 and 14) applied to
DEC IC710. IC710 in turn selects (by grounding) one zener diode to change the V Ref voltage used by motor
driver IC702/pin 20 for initial motor position. This change in reference causes a slight change in the voltage
applied to the motor that changes the monitor's viewing angle.
XAV-7W – Display
The 7" monitor is attached to the remainder of the car stereo from the back via two ribbon cables (Figure 3-8).
From the back of the monitor, all the adjustment controls listed in Table 3-3 are accessible (under the label).
Control
RV201 Brightness
RV207 R Sub Bright
RV208 RGB Amp
RV209 B Sub Bright
RV210 V Com
RV211 V Com Center
RV212 Gamma 0
RV213 Gamma 2
RV401 H Centering
RV402 Free Run Freq.
RV501 7.5Vdc level
RV503 5Vdc level
RV602 Inverter Voltage
RV900 DC / DC Converter Freq.
XAV-7W – Backlight Operation
The B&W display and backlight power come from the same power supply oscillator but different transformers.
Refer to Figure 3-10. LCD panels do not produce light, so they require a "backlight". The electro-luminescent
panel requires a regulated HV power supply for an even, flicker-free glow. This voltage comes from IC900, HV
Oscillator (Q608-Q610) and step up transformer T601. Once Sys B+ and LCD PW enter the board, HV is
produced and the backlight appears (one second ignition). Note: When there is no RGB input to an LCD module,
backlight is passed through on to the screen (white screen). The video input from the external XA-114 box
(RGB) and OSD graphics are mixed together at high-speed switch IC15 on the main board (not shown) prior to
IC201.
Table 3-3 - Monitor Controls
Name
Brightness
White balance
Color level
White balance
Black / White inversion point
Black / White inversion point
Linearity of gray scale
Linearity of gray scale
Horizontal Centering
H sync free run. 15.37kHz at TP70
Set voltage at TP58
Set voltage at TP57
HV set to backlight.
Set to 165kHz at TP88
Purpose
24
3. Display Products