Hughes Jvc 220 Projector Service Manual

Chapter 2---System Description 
H_RED+ Output of horiz. red centering (also top of the red horiz. yoke). Abou\
t 
+ 5 VDC. 
H_GRN+ Output of horz. green centering (top of green horz. yoke). About + 5 
VDC  
H_BLU+ Output of horiz. blue centering (top of blue horiz. yoke). About + 5 
VDC. 
V_RED+ Output of red vertical amplifier. About 40 VPP.  
V_GRN+ Output of green vertical amplifier. About 40 VPP. 
V_BLU+ Output of blue vertical amplifier. About 40 VPP. 
+15 V +15 V supply for use by Scan Reversal...

  Chapter 2---System Description 
 
Interlocks and protection: 
Input 
None 
Outputs 
H_LOCK + and H_LOCK-: Used to shut down the switching power 
supply of the horizontal deflection amplifier in the event of a loose 
yoke or loose scan reverse connector. This prevents the power 
supply section of the Horizontal/Vertical Deflection Board from 
operating when 1 or more yoke connectors are disconnected. 
/SWEEP_OK: Shuts down the video amplifiers in the event of 
deflection failure (if DEFL_OK or /H_ENABLE...

Chapter 2---System Description 
IIC_CLK
IIC_DATA
/IIC_SINT
X_RED_CONV
X_GRN_CONV
X_BLU_CONV
Y_RED_CONV
Y_GRN_CONV
Y_BLU_CONV
V_DRIVE
CORR_SYNC
WIDTH_CONTROL
RED_ILA+
RED_ILA-
GRN_ILA+
GRN_ILA-
BLU_ILA+
BLU_ILA-
X_RED-
X_GRN+X_GRN-
X_BLU+
X_BLU-
X_RED+
Y_RED-Y_GRN+
Y_GRN-
Y_BLU+
Y_BLU-
Y_RED+
H_PARABOLA
V_PARABOLA
V_RAMP
V_PARAB
2
3
4
2
4
6
810
12
17
18
5
J33
J31
J32
5+5.1V66ND7+15V9GND11-15V13GND
J32
1415
J3313
J31
J4012
3
4
5
6
J3912
3
4
5
6
J381
2
4
5
7
8
1GND
13GND
2GND
1GND
GND16
FROMSCB
FROM RTG...

  Chapter 2---System Description 
I 1 ILA_FREQ_N4 Data for selection of frequency of ILA bias circuit  
I 1 ILA_FREQ_N5 Data for selection of frequency of ILA bias circuit  
I 1 ILA_FREQ_N6 Data for selection of frequency of ILA bias circuit  
I 1 ILA_FREQ_N7 Data for selection of frequency of ILA bias circuit  
I 1 ILA_FREQ_N8 Data for selection of frequency of ILA bias circuit  
I 8 ILA_RED_BIAS Data for adjustment of red ILA bias 
I 8 ILA_GRN_BIAS Data for adjustment of green ILA bias 
I 8...

Chapter 2---System Description 
I 8 TP_KEY Data for adjustment of top/bottom keystone 
I 8 TP_KEY_BAL Data for adjustment of top/bottom keystone 
balance 
I 1 /RASTER_FIL Control line for the raster fill option, low = raster 
fill is active 
I 1 /CONV_ENABLE Convergence enable line low = enabled 
convergence 
O 1 ILA_LOCKED Status line for the lock indication of the PLL of the 
ILA section with high = locked PLL 
O 1 /CD_OK Convergence board status line. Low = 
operational C/D Board, High =...

  Chapter 2---System Description 
/IIC_SINT IIC interrupt line. Convergence board does not initiate any IIC 
interrupt. 
ILAS  
OUTPUTS DESCRIPTION 
RED_ILA+ The positive output of red ILA driver circuitry, about ± 12 VPP 
RED_ILA- The negative output of red ILA driver circuitry, about ± 12 VPP 
GRN_ILA+ The positive output of green ILA driver circuitry, about ± 12 VPP 
GRN_ILA- The negative output of green ILA driver circuitry, about ± 12 VPP 
BLU_ILA+ The positive output of blue ILA driver circuitry,...

Chapter 2---System Description 
 
X_GRN+ Output of green horizontal (X) convergence amplifier 
X_BLU+ Output of blue horizontal (X) convergence amplifier 
Y_RED+ Output of red vertical (Y) convergence amplifier 
Y_GRN+ Output of green vertical (Y) convergence amplifier 
Y_BLU+ Output of blue vertical (Y) convergence amplifier 
HORIZONTAL/VERTICAL DEFLECTION BOARD 
INPUTS DESCRIPTION 
WIDTH_ 
CONTROL 
A DC wave form for controlling width of picture. About 4 V max. 
OUTPUTS DESCRIPTION 
V_PARAB Vertical...

  Chapter 2---System Description 
2.3.10 Scan Reversal Board  
The Scan Reversal Board (SRB) is mounted vertically on the right 
side of the card cage.  
The following functions are provided by the SRB: 
• Reversal of scan in both horizontal and vertical axes 
• Horizontal width adjustment for each color (R, G &B) 
• Horizontal current feedback 
• Scan failure detection for all six main (horizontal and vertical) 
deflection amplifiers 
The Scan Reversal Board Input/Output diagram (Figure 2-16) and 
the...

Chapter 2---System Description 
 
Figure 2-16.   Scan Reversal Board, Input/Output Diagram. 
Scan Reversal Board I /O 
This section describes the inputs to and outputs from the SRB. 
The I/O descriptions are arranged by the source/destination of the 
signal. The assembly communicated with is the primary heading 
of each group of signals. Those signals are subdivided into inputs 
and outputs. Input refers to an Input to the Scan Reversal Board. 
Output refers to an output from the Scan Reversal Board....

  Chapter 2---System Description 
Table 2-19.  Scan Reversal Board I/O signals 
HORIZONTAL / VERTICAL DEFLECTION BOARD
INPUTS DESCRIPTION 
H_OUT_ 
FLYBACK Horizontal output flyback pulse, about 800 VPP 
H_LOCK+ Horizontal interlock for yoke connectors. This should be about 5 
V when closed or 15 V when open. 
H_RED+ Output of horizontal red centering (also top of the red horiz yoke). 
About + 5 Vdc. 
H_GRN+ Output of horizontal green centering (also top of the green horiz 
yoke). About + 5 Vdc. 
H_BLU+...