Chapter 2—Functional Description
Model 330, 340SC and 370SC Service Manual
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System Power Supply
Inputs
Description
+107V
Power supply to cathode drive amplifier.
+6.3V
Power supply to filament.
+15V
Power for analog components.
-15V
Power for analog components.
GND
Return for power supplies.
ARC GND
Low impedance return path to HVPS for arc currents.
System Controller Board P/N 104668 (SCB)
The system controller board plugs into the electronics card cage. It is the middle
board in the card cage (third from the front).
The following functions are provided by the SCB:
Operator Interface:
IR Interface.
RS232 Interface.
On-Screen Menus.
Dot Matrix Display.
Inter Board Communications and Control:
IIC Bus (Overall system control).
Serial Bus.
Power Supply Interface.
Projector operation:
Direct operation of the projector by issuing commands based on
external directives and internal information.
Contains program and working memories.
Generate Overlays:
Digital Test Patterns.
Gray-Scale.
Provide Convergence Correction Outputs:
X and Y Axis Correction.
Sensitivity and Threshold Correction.
The block diagram (see Figure 2-17) description, along with the I/O description in
the section following, provide information to perform module-level
troubleshooting.